Answer: Option C.
When two receive genes for a trait are presence.
Step-by-step explanation:
Recessive allele or genes is the gene that is not expressed in a trait when there a dorminant gene. It's effect is always masked by dorminant gene .
A recessive trait can be expressed phenotypically if a person inherit
homozygous recessive allele.
For example the recessive allele for dwarf is t. If a person inherit two receive allele for dwarf need (tt), the dwarf trait will be expressed phenotypically.