All elderly tend to be more susceptible to infection because of:

Correct option is A

Ans. (a)
Sol. Aging naturally leads to immunosenescence, which is a decline in immune function, particularly in T-cell mediated immunity. This makes elderly individuals more prone to infections, delayed healing, and poor response to vaccinations.
Explanation of each option:
· (a) A decline in immune function – Correct answer. Aging reduces the body's ability to fight infections due to weakened immune responses.
· (b) Poor nutritional status – Can contribute but is not universal; not all elderly have malnutrition.
· (c) Increased exposure to pathogens – Elderly are not necessarily more exposed, but rather less capable of fighting infections.
· (d) Lack of exercise – May affect general health but is not the primary reason for increased susceptibility to infection.