Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R). 

Assertion (A) : Pleura help in reducing friction on the lung surface.

Reason (R) : The pleural fluid present between the two pleural membranes acts as a lubricant. 

In light of the above statements, choose the correct answer from the options given below.

The pleura is a thin, double-layered membrane that surrounds the lungs and lines the inside of the chest cavity. Its primary function is to reduce friction between the lungs and the chest wall during breathing movements. The outer layer of the pleura, called the parietal pleura, lines the inside of the chest cavity, while the inner layer, called the visceral pleura, covers the surface of the lungs. Between these two layers is a small amount of fluid that acts as a lubricant, allowing the lungs to move smoothly within the chest cavity during breathing without causing friction or discomfort. This lubricating function is crucial for efficient lung expansion and contraction during respiration.