priyankamishra11 wrote:Although reclusive author Harper Lee wrote just one book in her lifetime and that book is widely considered a masterpiece.
1- lifetime and that book
2- lifetime and it
3- lifetime, that book
4 - lifetime; it
5- lifetime; that book
I got the right answer 3.
Is use of comma before THAT is justified.?
Here we have two independent clauses:
1) reclusive author Harper Lee wrote just one book in her lifetime;
and
2) that book is widely considered a masterpiece.
Two independent clauses must be connected by 1 and only 1 connector.
"Although" appears in the non-underlined part of the sentence, so that's the only connector that we're allowed to use.
(1) and (2) both have "and", a second connector. Eliminate (1) and (2).
(4) and (5) both have a semicolon. Semicolons can precede a connector, but rarely, if ever, follow an introductory clause that begins with a connector. Elminate (4) and (5).
Only (3) has no connector issues: choose (3).
In this question we need "that book" because "it" would properly refer to "her lifetime", not the "one book" - another reason to eliminate (2) and (4).
Technically your original comment raises a good point - we would use "which book" (or just "which" if we didn't have a modification issue) instead of "that book" if we're just adding a parenthetical comment to the first part of the sentence. However, if we look at the sentence as composed of two independent clauses, "that" is correct.