In a typical Mendelian dihybrid cross, one parent is homozygous for both dominant traits and another parent is homozygous for both recessive traits. In the F₂ generation, both parental combinations and recombinants type appear. The phenotypic ratio of parental combinations to recombinants is

• A

  15 : 1

• B

  12 : 4

• C

  9 : 7

• D

  10 : 6