Producers of many mouthwash brands claim that using mouthwash prevents tooth decay. what is the best conclusion regarding these mouthwash brands and bacteria in the mouth?
a. mouthwash contains ingredients that kill harmful bacteria.
b. mouthwash contains bacteria that produce oxygen.
c. mouthwash does not really work because the growth of harmful bacteria cannot be prevented.
d. mouthwash does not really work because bacteria is not known to directly cause tooth decay.

Some species of wasps are social. the queen starts a colony from scratch each spring. she builds a small nest, and lays and raises a group of female workers. the workers enlarge the nest while the queen continues to lay eggs. unfertilized eggs become males that mate with newly hatched females. all of the wasps except the newly fertilized females die by the summer. which best describes this behavior? a)it is beneficial only to the males that do not fertilize eggs. b)it is beneficial only to the female workers that are not fertilized. c)it is beneficial to each one of the individual colony members. d)it is beneficial to the whole species, but not to all of the individual members.