A Population of 500 Field Mice Exhibits Black or Grey

A population of 500 field mice exhibits black or grey coat colours in approximately equal proportions.An individual mouse has a mutation that results in a brown coat colour;this mutation is passed along to many of its 20 offspring,who also exhibit a brown phenotype.If frequency-dependent selection is operating,which of the following would be true?

A) Mice within the population would breed nonrandomly to avoid inbreeding depression.
B) Mice with the brown phenotype would have a higher fitness relative to individuals with black or grey coat colour.
C) Mice with the brown phenotype would have a lower relative fitness to individuals with black or grey coat colour.
D) Mice with the brown phenotype would have higher relative fitness if they were heterozygous.
E) There would be more heterozygous individuals in the population than expected according to HWE. F) It is impossible to determine unless the type of selection is known.