$P -$ Statement: Small disc-shaped structures called kinetochores are present on the surface of centromeres.
$Q -$ Statement: Spindle fibers attach to the centromeres of chromosomes.

• A
  Both statements $P$ and $Q$ are correct,and statement $P$ is the correct explanation of statement $Q$.
• B
  Both statements $P$ and $Q$ are incorrect.
• C
  Statement $P$ is incorrect. Statement $Q$ is correct.
• D
  Both statements $P$ and $Q$ are correct.