Allen was adopted at an early age by a Japanese American couple. As a result, he grew up speaking both Japanese and English fluently. In terms of genetics, this manifestation of Allen's ability to speak is an example of a(n) _______.

A) genotype
B) phenotype
C) mutation
D) alarm reaction

Allen's ability to speak both Japanese and English fluently is an observable trait or phenotype, which is influenced by both his genetic makeup (genotype) and environmental factors such as being adopted into a Japanese American family and exposed to both languages from an early age. A mutation (C) refers to a change in DNA sequence, which may or may not result in a visible phenotype. The alarm reaction (D) is a physiological response to stress.