Especially the first blank is tricky.



There is a rising consensus amongst immunologists that the observed rise in allergies in the general population can be attributed to (i) ______ exposure to everyday germs.

(A) frequent
(B) decreased
(C) heightened

of the 3 blanks, C is clearly out of scope. However, looking at the first sentence we do not have so many clues to have a trade-off. A and B are a possible answer like. Move on and see if the second sentence will help us


Known as the hygiene hypothesis, this counterintuitive idea could have far-reaching implications; for one, we may now have to be more (ii) ______ those paternal prescriptions to scrub our children’s hands at every opportunity.


The fact that allergies increase is called the hygiene hypothesis. So far so good. This counterintuitive: this word is a huge clue because it suggests us that in the first sentence something is on the contrary side of what we could think. That is the meaning of counterintuitive. it is an odd solution. Moreover, we may now have to be more (i) ______ those paternal prescriptions to scrub our children’s hands at every opportunity.

The red part means that those idea to scrub the babies at every time as previously thought by parents is wrong whatsoever. So among the choices, indifferent to is wrong because we ara talking of an issue that matters. Cross off.

Cognizant to is someone that is aware of a certain scenario. However, we said that what the parents did til now is probably wrong. As such, we should be diffident of a usual practice. Cross off.

D is the answer.

Now back to the first blank, frequent is wrong just because in the second part we are saying that just the frequent use and abuse of a practice (scrubbing every time, is wrong). So, the less frequent exposition to the germs is the cause of the allergies (at least partially. In fact, if you read something on the internet about healthy manners: the decrease exposition to the germs is the real cause because our immune system is not prepared to the germs' attacks. We do have few defenses.

B is the answer.

C is clearly out of scope.

Hope this helps.

Regards

yes, perfect

Counterintuitive was the most important clue. It means it would be against the norm. They're talking about hygiene so it must be related to cleanliness. But since it's counterintuitive so it must be opposite of cleanliness.