Animal breeding is producing improved breeds of ...$A$.. by improving their ...$B$... through selective mating. Here $A$ and $B$ refer to:

• A
  $A-$domesticated animals,$B-$phenotype
• B
  $A-$wild animals,$B-$genotype
• C
  $A-$domesticated animals,$B-$genotype
• D
  $A-$wild animals,$B-$phenotype