Hypothetical plant hormones areA. FlorigenB. VernalinC. Florigen and vernalinD. Auxin

The correct answer is C. Florigen and Vernalin.

Explanation:

Florigen: This is a hypothetical plant hormone that is believed to play a role in the initiation of flowering. It was proposed as a factor responsible for the transition from vegetative growth to flowering in plants, but it has not been fully isolated or identified as a specific molecule. It is thought to be produced in the leaves and transported to the apical meristem, where it induces flowering.

Vernalin: This is another hypothetical hormone, thought to be involved in the process of vernalization (the requirement of cold exposure for flowering in certain plants). Like florigen, it has not been fully identified or isolated but is considered to be involved in the regulation of flowering under specific conditions (e.g., cold temperatures).

Auxin: This is a well-known and identified plant hormone involved in the regulation of growth, elongation, and differentiation of cells, as well as processes like phototropism and gravitropism. However, auxin is not involved in the hypothetical regulation of flowering like florigen or vernalin.

Thus, the answer is C because both florigen and vernalin are hypothetical hormones that play roles in flowering.