Hypersensitivity is related to

a) Aberrant functioning of the immune system
b) Increase in ambient temperature
c) Age of individual
d) Food habits

Ans – [A] 

Explanation – Hypersensitivity (also called hypersensitivity reaction or intolerance) is a set of undesirable reactions produced by the normal immune system, including allergies and autoimmunity. These reactions may be damaging, uncomfortable, or occasionally fatal.