BenCrackVerbal wrote:
Retroviral injections prove to be the only effective means of treating some serious diseases. Nevertheless, it cannot be stated that retroviral injections are always beneficial for human health, since they are known to reduce immune system activity in some cases, and persons with reduced immune system activity are likely to be afflicted by various infectious diseases.
Which of the following statements can be properly inferred from the passage above? (A) Retroviral injections are the major cause of reduced immune system activity.
(B) Treatment of some serious diseases always results in reduced immune system activity.
(C) Retroviral injections are not beneficial for human health.
(D) People who contract serious diseases will be afflicted by various infectious diseases.
(E) Retroviral injections are the only effective means of treating some infectious diseases.
My approach to CR:
Start with the question stem. Here the question stem indicates that the task in hand is to 'infer'.
Summarise the argument:
RVI "only" effective way to treat some serious diseases.
RVI "not always" beneficial to human health. This leads to reduced immune system activity (ISA) thereby contracting an infectious disease.
Since the question does not refer to any specific text or any specific part to be inferred, let's look at the options for some help. (Skipping Pre-thinking)
(A) Retroviral injections are the major cause of reduced immune system activity.
RVI reduces ISA in "some cases". This does not necessarily mean that RVI is the major cause of reduced ISA.
(B) Treatment of some serious diseases always results in reduced immune system activity.
RVI is only effective in some serious diseases.
RVI leads to reduced ISA in some cases.
It can be inferred that 'some serious diseases' and 'some cases' overlap. And inferring this will also retain the argument logic intact.
(C) Retroviral injections are not beneficial for human health.
RVI is 'not always' beneficial for human health. It means that sometimes RVI can be beneficial. However, the option is a complete 180 deg.
(D) People who contract serious diseases will be afflicted by various infectious diseases.
Only those with reduced immunity will be afflicted by infectious diseases not everyone. So this cannot be inferred.
(E) Retroviral injections are the only effective means of treating some infectious diseases.
RVIs are only effective in treatment of 'some serious diseases' which can be 'infectious' or 'non-infectious' and this distinction is not discussed in the stimulus.
Here the larger challenged I faced was to decide between options B and D but if one pays close attention to verbs such as 'will', 'likely', 'only' (determinative/probabilistic verbs), he/she will be able to figure out the correct option.
Hit Kudos if you like the explanation.