Premise - Thousands die due to heart attack before reaching a hospital or clinic where they can benefit from the drugs that dissolve clots.
Conclusion - The new blood clot dissolving agent could save the lives of many people from heart attack.

Prethink :
With effectiveness being similar to those of the drugs,the new agent will have an advantage over the drugs only if it does not have dependencies on the hospitals. If the dependency on the hospitals remains as it is with drugs, the conclusion is not attack-proof.

(A) The new agent must be administered by a team of doctors in a hospital or clinic setting.
If this is true,the agent too can't help much in controlling heart attacks as the thousands dies before reaching the hospitals.
(B) Many heart attack victims die unnecessarily even though they reach a hospital or clinic in time
Even if many die even though they reach a hospital or clinic in time, the new agent may be at-least as effective as the drugs and hence does not weaken the fact that it could save many lives from heart attack.
(C) The new agent can be effectively administered prior to the victim's arrival at a hospital or clinic
If so, this closes the gap that the drugs have. This strengthens the conclusion.
(D) The Food and Drug Administration has already approved agents that are at least as effective as the new drug in dissolving blood clots
This is the basic assumption for the conclusion. If the agents are not at least as effective as the new drug are, the conclusion falls apart.
(E) The new blood clot dissolving agent causes kidney damage and irregular heart rates in some patients.
This is promising as the information talks about the disadvantages of the agent. But, this weakness is not as strong as in A for the two reasons:
1. We don't know how many does "some patients" refer to. - If thousands are getting benefitted and only 1-2 are getting kidney damage, it's still better than dying due to heart attack.
2. We have no information of the side-effects of the drugs - What if the similar side effects are there with the drugs? If so, the conclusion still sustains.

IMO A

Thousands who suffer heart attacks each year die before reaching a hospital or clinic where they can benefit from the drugs that dissolve clots in coronary arteries. The Food and Drug Administration recently approved a new blood clot dissolving agent, which a spokesman claimed could save the lives of many people who would otherwise join this group of heart attack victims.

Options of this question are very close and tricky. So, it's very importnat to stick to the conclusion.
Conclusion: a new blood clot dissolving agent could save the lives of many people.
Given:
- Thousands die before reaching a hospital or clinic where they can benefit from the drugs that dissolve clots in coronary arteries.
- So we already know that there exists some drug that can dissolve the clot can save the life

So any information that can provide support to the statement that "new drug is similar to other drugs or have some other shortcoming that could impact saving of lives" will weaken the conclusion

Which of the following, if true, would seriously weaken the argument above?

(A) The new agent must be administered by a team of doctors in a hospital or clinic setting.
- So, this statement is saying that new drug can not be administered before reaching a hospital or clinic. - Weakner
- CORRECT

(B) Many heart attack victims die unnecessarily even though they reach a hospital or clinic in time
- Conclusion is based on the premise that "Thousands die before reaching a hospital or clinic"
- It does not matter what happens after reaching the hospital

(C) The new agent can be effectively administered prior to the victim's arrival at a hospital or clinic
- this statement is strengthening the conclusion

(D) The Food and Drug Administration has already approved agents that are at least as effective as the new drug in dissolving blood clots
- We already know, such drugs do exist. So, it is not weakening the conclusion in any manner

(E) The new blood clot dissolving agent causes kidney damage and irregular heart rates in some patients.
- We do not know that other existing drugs may have the worst side effect than the new drug - Strengthener in this case
- Argument is about saving lives and not about the side effects

Official Explanation:

A

Step 1: Identify the Question Type

The word “weaken” in the question stem is the clearest indication of a Weaken question.

Step 2: Untangle the Stimulus

The argument we’re seeking to weaken is that of the FDA spokesperson, who claims that the new blood clot–dissolving agent approved by the FDA could save the lives of people who would otherwise die of their heart attacks before reaching a hospital or clinic.

Step 3: Predict the Answer

The spokesperson’s conclusion can be characterized as a prediction. Before evaluating the choices, let’s determine what would have to happen in order for that prediction to come true. In order for the blood clot–dissolving agent to save these lives that the spokesperson mentions, it would have to be administered before people get to the hospital, since that’s the critical life-saving window. So to weaken the argument, we need an answer that demonstrates that this won’t happen.

Step 4: Evaluate the Choices

It doesn’t get much more straightforward than (A), which is the correct answer. If the agent must be administered in the hospital, then it doesn’t do this group of people any good, since they ordinarily die before they can get to the hospital. (B) doesn’t weaken the argument because it doesn’t tell us that the new dissolving agent won’t help these heart-attack victims. (C) strengthens the argument by suggesting that paramedics will have a chance to save victims without having to bring them to the hospital first. (D) has no effect; even if there are other agents out there, that doesn’t mean that this new agent won’t be helpful. And (E) does introduce some potentially nasty side effects, but the spokesperson doesn’t argue that the new agent won’t cause side effects; he merely argues that the drug will save lives. Choice (A) is correct.
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