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:

• A
  $(A)$ is false but $(R)$ is true
• B
  $(A)$ is true but $(R)$ is false
• C
  Both $(A)$ and $(R)$ are true and $(R)$ is the correct explanation of $(A)$
• D
  Both $(A)$ and $(R)$ are true but $(R)$ is not the correct explanation of $(A)$