Question

many mosquito repellents contain natural components that work by activating multiple odor receptors on mosquitoes antennae. as the insects develop resistance, new repellents are needed. ke dong and her team found that ebf, a molecular component of a chrysanthemum - flower extract, can repel mosquitoes by activating just one odor receptor - and this receptor, or31, is present in all mosquito species known to carry diseases. therefore, the researchers suggest that in developing new repellents, it would be most useful to
14 which choice most logically completes the text?
a identify molecular components similar to ebf that target the activation of or31 receptors.
b investigate alternative methods for extracting ebf molecules from chrysanthemums.
c verify the precise locations of or31 and other odor receptors on mosquitoes antennae.
d determine the maximum number of different odor receptors that can be activated by a single molecule.

Explanation:

The text emphasizes that EBF repels mosquitoes by activating the Or31 receptor present in disease - carrying mosquito species. To develop new repellents, it makes sense to find similar molecular components that target the activation of Or31 receptors. Option B focuses on extraction methods rather than the key receptor - targeting aspect. Option C is about receptor locations which is not the main focus for developing new repellents. Option D is about the maximum number of receptors activated by a single molecule, which is not relevant to the context of using Or31 for new repellents.

Answer:

A. identify molecular components similar to EBF that target the activation of Or31 receptors.