Given below are two statements regarding the circulation of blood in fishes.
Statement $I$: The heart of a fish contains only deoxygenated blood.
Statement $II$: Fishes show single circulation,and blood passes through the heart only once during each cycle.
In light of the above statements,choose the correct answer from the options given below.

• A
  Both statement $I$ and statement $II$ are correct.
• B
  Both statement $I$ and statement $II$ are incorrect.
• C
  Statement $I$ is correct and statement $II$ is incorrect.
• D
  Statement $I$ is incorrect and statement $II$ is correct.