Isn't this correct?! (I chose A). My teacher marked it incorrect.

What is a phenotype?

A. the physical or detectable traits of an organism

B. a type of biological diversity caused by environmental factor that affects the

organism

C. the alleles an organism inherits from its grandparents

A phenotype (from Greekphainein, meaning "to show", and typos, meaning "type") is the composite of an organism's observable characteristics or traits, such as its morphology, development, biochemical or physiological properties, phenology, behavior, and products of behavior (such as a bird's nest).