[tex] \boxed{ \frak\pink{Answer}}[/tex]
The correct option is:
(B) Sarah, who is very smart, sits with me at lunch.
[tex] \boxed{ \sf\blue{Explanation}}[/tex]
Here, before first coma, it is said about the person. And before second coma, it is said about the person's quality.
So, we conclude option (B) is correct.
[tex] \boxed{ \frak\pink{Keep \: Learning}}[/tex]
