While the nurses frantically searched for his parents to collect his v

OFFICIAL SOLUTION

Now what does this question tell us (apart from borderline neglectful parenting)? The boy was injured at some point and then explained things to the doctor while the nurses tried to call the parents. The timeline makes perfect sense in this regard, and therefore we can look through the answer choices for any contradictions to this timeline. Answer choice C will be eliminated for this reason as it indicates that the boy was injured while the nurses tried to call his parents, creating a nonsensical timeline. Why would the nurses call the boy’s parents if he were fine? Clearly he would have to have been injured before any calls were made (even if they were collect calls).

This leaves us with four viable answer choices. Looking at them one by one, answer choice A seems reasonable, but answer choice D says exactly the same thing in almost the exact same way. It will therefore be hard to differentiate between these two choices. Answer choice B incorrectly messes with the timeline as well, so it can be eliminated. Answer choice E is exactly the same as the initial sentence with the verb tense updated to the present. This is a clear decision point as only one of the two answer choices can be correct. To determine which one is correct, we need to revisit the concept of universality.

Compare the following two sentences:

“In 2010, I moved to Montreal, which was an island”

and

“In 2010, I moved to Montreal, which is an island”

Since the move was several years ago, it makes sense that the verb “moved” is in the past. However, Montreal was an island in 2010, and is still an island in 2013 (although half the bridges are now falling down). Using the past here is only correct if something happened in the interim to change the status of Montreal. For example, had Montreal been destroyed, Krakatau style, then the first sentence would have been correct. Since Montreal is still here, nothing has changed since the move, and the present tense is correct.

Going back to the injured boy, since he is in the process of explaining his blood type to the doctor, he clearly isn’t deceased, which would have been the only justification for using the past tense. As such, the boy is fine and he is still O positive, a universal truth that will not spontaneously change. Answer choice E is correct because Answer choices A and D both erroneously use the past tense.

When evaluating universal truths, it is important to keep in mind that unchangeable elements will always remain in the present. When dealing with transitory elements, the timeline must be consistent with a changing reality.  When dealing with something as intractable as blood types, you can be positive (which is my blood type!) that they will never change.