Assertion (A): Formation of rust is a chemical change. Reason (R):...

Assertion (A): Formation of rust is a chemical change. Reason (R): For rust to form, iron must be exposed to air and water.

A. Both A and R are true, and R explains A

B. Both A and R are true, but R does not explain A

C. A is true, but R is false

D. A is false, but R is true