All of the following are true of hypersensitivity except
a. it occurs in the presence of an antigenb. it is synonymous with allergyc. it occurs when an individual is exposed to an allergen for the first timed. it is due to an altered immune responsee. it requires previous exposure to an antigen

The correct option is C.

Explanation:

Hypersensitivity is the process by which the immune system produce excessive reactions when exposed to certain antigens. There are four types of hypersensitivity, type 1 to type IV.

For hypersensitivity to occur some conditions must be fulfilled. For instance, an antigen must be present, the immune system must have been exposed to the antigen previously, etc. Hypersensitivity does not occur when the immune system is been exposed to an antigen for the first time.

oxygen +1 most likely

the electromagnetic energy from the sun arrives in the form of visible and invisible light.