Question

what is the role of the serous membranes covering some organs?
to provide a protective outer covering for the organ
to serve as extra tissue for blood flow to the organ
to prevent friction between the organ and body cavity wall
to provide passage of nutrients for the organ tissues

Explanation:

Serous membranes (like pleura, peritoneum) secrete serous fluid. This fluid reduces friction between organs and body cavity walls (or other organs) during movement (e.g., breathing, digestion). The first option is incorrect as the protective outer covering is more like the visceral layer, but the main role of serous membranes is reducing friction. The second option is wrong as serous membranes aren’t for blood flow. The fourth option is incorrect as nutrients are delivered via blood vessels, not serous membranes.

Answer:

C. to prevent friction between the organ and body cavity wall