Mendels dihybrid crosses, but not his monohybrid crosses, show that

Mendels dihybrid crosses, but not his monohybrid
  crosses, show that
  a. some genes are linked together.
  b. the two alleles controlling a trait are divided
  equally among the gametes.
  c. alleles for different traits are inherited
  independently.
  d. one of the pair of alleles is dominant to the
  other.
  e. the crossing of two different homozygous forms
  will not produce any offspring in the first
  generation that will look like either of the
  parents.

Question 2

Mendel would not have seen four different
  phenotypes in the F2 generation of his dihybrid
  crosses if
  a. the genes were on the same chromosomes.
  b. the P1 generation was homozygous.
  c. purple was dominant to white.
  d. more than two traits were traced.
  e. all of these are true.