Select the correct option based on statements below:

Assertion (A): Aldehydes and ketones both react with Tollen’s reagent to form a silver mirror.
Reason (R): Both aldehydes and ketones contain a carbonyl group.
 
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.