Answer:
B. WW or Ww
Explanation:
If the w allele is recessive, that means that the presence of any W alleles will mask the expression of the w allele. So the possible genotypes for no spots and hence solid coat, keeping in mind that there must be two alleles, one from each parent, are WW or Ww.
WW or Ww would both produce phenotypically solid coats. ww would produce a spotted coat.
