Which layer of the meninges is thick and opaque?

A) Arachnoid mater
B) Infundibulum
C) Dura mater
D) Mammillary body
E) Pia mater

Which of the following would likely increase the likelihood of fixing a beneficial allele in a population of finite size?

A) a higher starting frequency to decrease likelihood of drift
B) a larger excess fitness to increase selection for the beneficial allele
C) a larger population size because selection will be greater in a larger population
D) all of the above
E) none of the above