Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : In expensive scientific instruments, silica gel is kept in watch-glasses or in semipermeable membrane bags.

Reason (R) : Silica gel adsorbs moisture from air via adsorption, thus protects the instrument from water corrosion (rusting) and / or prevents malfunctioning.

In the light of the above statements, choose the correct answer from the options given below :

1. A Both (A) and (R) are true and (R) is the correct explanation of (A) Correct answer
2. B (A) is true but (R) is false
3. C (A) is false but (R) is true
4. D Both (A) and (R) are true but (R) is not the correct explanation of (A)