Determine the correctness or otherwise of the following Assertion (A) and Reason (R).
Assertion: An antigen recognized by one immunoglobulin subtype is not recognized by any other subtype.
Reason: Immunoglobulin subtypes differ from each other both in the variable and in the constant regions.

A. Both (A) and (R) are true and (R) is the correct reason for (A)

B. Both (A) and (R) are true but (R) is not the correct reason for (A)

C. Both (A) and (R) are false

D. (A) is true but (R) is false

Answer: Option C