Concept:Dihybrid inheritance deals with the simultaneous inheritance of two pairs of contrasting characters.
Explanation:The prefix “di-” means two.
Mendel carried out crosses between plants that differed in two pairs of contrasting traits.
For example, he considered seed shape along with seed colour together.
Each pair has two opposite forms, such as round versus wrinkled and yellow versus green.
So a dihybrid cross tracks two characters at the same time.
A cross involving only one pair of contrasting characters is called a monohybrid cross.
Options C and D mention three or four pairs, which would be trihybrid or tetrahybrid inheritance.
Therefore, the correct meaning of dihybrid inheritance is the study of two pairs of contrasting characters.
Answer:B. two pairs of contrasting characters