Final answer:
The body parts considered mucous membranes are the eyes, nose, and mouth, as they all produce mucus or tears that serve as barriers to pathogens, making the correct answer 'All of the above'.
Step-by-step explanation:
The body parts that can be considered mucous membranes include the eyes, nose, and mouth. This is because mucous membranes line various body parts exposed to the external environment and produce mucus, which serves as a mechanical barrier to pathogens. Specifically: eyes produce tears that wash away pathogens, the nose is lined with mucous membranes that can eject pathogens when you sneeze or cough, and the mouth is the first organ of the gastrointestinal tract lined with mucous membrane that helps in moistening, softening, and lubricating food as part of the digestive process. Therefore, the answer to the question is D) All of the above.