Statement $X$: In animals,the proportion of homozygosity can be increased in heterozygotes.
Reason $Y$: Inbreeding is performed in animals.

• A
  Both Statement $X$ and Statement $Y$ are true. $Y$ is the correct explanation of $X$.
• B
  Both Statement $X$ and Statement $Y$ are true. $Y$ is not the correct explanation of $X$.
• C
  Statement $X$ is false and Statement $Y$ is true.
• D
  Both Statement $X$ and Statement $Y$ are false.