$A$ - Inbreeding refers to the mating of more closely related individuals within the same breed.
$B$ - Inbreeding increases heterozygosity only.

• A
  $A$ and $B$ both correct
• B
  $A$ and $B$ both incorrect
• C
  $A$ is correct and $B$ is not correct
• D
  $A$ is not correct and $B$ is correct