By the Early 1980s, the Population of Florida Panthers Had

By the early 1980s, the population of Florida panthers had dwindled to fewer than 30. Within this population, there was a high frequency of detrimental traits, including low sperm count and undescended testicles in males and kinked tails in both sexes. The future for this iconic population was bleak at best. Which of the following provides the BEST explanation for the observed detrimental traits?

A) The mutation rate in this population is very high due to the small number of individuals.
B) Natural selection is acting in this population and resulting in more individuals with detrimental traits.
C) Migration of individuals into this population has introduced more detrimental traits.
D) The population is experiencing a genetic bottleneck, where the genetic variation is declining and harmful alleles are drifting to high frequencies.
E) Recurrent mutation and natural selection are acting as opposing forces on this population and an equilibrium has not yet been reached.