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).

some fungi obtain their nutrients from a living host (plant or animal) and are called most biotrophic fungi have fairly narrow host ranges—they are specialized on a limited called rhizomorphs that allow the fungus to grow from one tree to another. ascospores are formed inside a sac-like structure called an ascus. so your answer is a