Which one of the following represents pulmonary circulation?

• A
  $Left \text{ atrium} \rightarrow \text{Lungs} \rightarrow \text{Right atrium}$
• B
  $Left \text{ atrium} \rightarrow \text{Lungs} \rightarrow \text{Right ventricle}$
• C
  $Right \text{ ventricle} \rightarrow \text{Lungs} \rightarrow \text{Left ventricle}$
• D
  $Right \text{ ventricle} \rightarrow \text{Lungs} \rightarrow \text{Left atrium}$