Question

Which of the following has a strong sense of smell?
A. Dogs
B. Cats
C. Mosquitoes
D. Both A and C

Answer 1

Hint: Sense of smell is the one of five special senses through which an individual smell or odour is perceived. The sense of smell has several functions, including detecting hazards, and pheromones, and plays a role in taste. Sense of smell differs in different animals, some of which have keener abilities than others. In general, mammals are good at smelling as compared to other vertebrates.

Complete answer:
Option A: Dogs have evolved to possess a robust sense of smell. They possess up to 300 million olfactory receptors in their noses, with approximately \[900\] genes that code for smell receptors. Even in short-nosed breeds, the olfactory centre is comparatively highly developed.
So, option A is correct.
Option B: Cats have somewhere around \[50\] million to \[80\] million odor-sensitive olfactory receptor cells in their nose. This means that cats have far fewer scent receptors than dogs.
So, option B is not correct.
Option C: Mosquitoes suck the blood of human beings as food, hence they're stimulated by several factors, especially smell. Initially, they're attracted by the \[C{O_2}\] we exhale. Body heat is perhaps important too, but once the mosquito gets closer, she is going to answer the smell of a possible blood source's skin. Even if it were possible to carry one's breath indefinitely, another human breathing nearby, or several meters upwind, would create a \[C{O_2}\] plume that would lead mosquitoes close enough to you that they'll lock on to your visual signature.
So, option C is correct.
Option D: Since we see that dogs and mosquitoes have a robust sense of smell. Therefore, the right answer is both A and C.
So, option D is correct.

Therefore, Option D is the correct answer.

Note:
Dogs have an equivalent five senses as humans. However, some are more highly developed, et al. are deficient compared with those of humans. Dogs’ sense of smell is far and away the foremost acute and is immeasurably better than that of humans. Dogs can detect drugs, explosives, and therefore the scents of their masters. The dog’s sense of taste is poorly developed compared to humans. If forced to measure on their own, dogs will eat almost anything without much discrimination. Cats are ready to smell far better than people, but not as well as dogs.