The leaf beetle, Chrysomela aeneicollis, lives in the Sierra Nevada Mountains of California. Scientists studying the beetles found that exposure

to high temperatures during the summer, when the eggs are laid and the

larvae are developing, causes physiological stress. The impact is on

metabolic enzymes and heat shock protein expression. One allele, pgi-4,

increased in frequency in the beetle population that was exposed to hotter,

drier summers in the Sierra Nevada Mountains.

If the temperature in the Sierra Nevada Mountains continues to increase,

what will happen to the frequency of the pgi-4 allele?

A. Increase

B. Decrease

C. Stay the same

Use your knowledge of evolution and natural selection to explain your

answer