Assertion A: Hydrolysis of an alkyl chloride is a slow reaction but in the presence of NaI, the rate of hydrolysis increases.
Reason R: $$I^-$$ is a good nucleophile as well as a good leaving group.
In the light of the above statements, choose the correct answer from the options given below.

Assertion A: Hydrolysis of an alkyl chloride is a slow reaction but in the presence of NaI, the rate of hydrolysis increases.

This is true. Alkyl chlorides undergo slow hydrolysis because Cl$$^-$$ is not as good a leaving group. When NaI is added, the I$$^-$$ ion (which is a good nucleophile) first displaces the Cl$$^-$$ via SN2 to form an alkyl iodide (Finkelstein reaction). The alkyl iodide then undergoes hydrolysis much faster because I$$^-$$ is a much better leaving group than Cl$$^-$$. This two-step process is faster overall than direct hydrolysis of the alkyl chloride.

Reason R: I$$^-$$ is a good nucleophile as well as a good leaving group.

This is true. I$$^-$$ is a good nucleophile (it attacks the carbon in alkyl chloride) and also a good leaving group (it leaves easily in the subsequent hydrolysis step). Both properties are needed to explain the catalytic effect of NaI.

Moreover, R is the correct explanation of A. The reason NaI accelerates hydrolysis is precisely because I$$^-$$ can act as a nucleophile to displace Cl$$^-$$ (forming R-I) and then I$$^-$$ leaves readily during hydrolysis (since it is a good leaving group).

The answer is Option C: Both A and R are true and R is the correct explanation of A.