Detailed Instructions: In this task, you will be given sentences in which your task is to recognize the name of the organ of the body. An organ is a collection of tissues that structurally form a functional unit specialized to perform a particular function. Although there might be several correct answers, you need to write one of them.
Q:  Two siblings presented with typical clinical features of congenital pulmonary alveolar proteinosis ( PAP ) .
A:
pulmonary