Question

Identify the correct sentence. A. It was late so​ I, went to bed. B. It was​ late, so I went to bed. C. ​It, was late so I went to bed. D. It was late​ so, I went to bed.

Answer 1

Answer: The right answer is the B) It was​ late, so I went to bed.

Explanation: Just to elaborate a little on the answer, it can also be added that commas are used to separate independent clauses, like the ones in the example—"It was late" and "I went to bed—when they are linked or joined by a coordinating conjunction such as so. When that's the case, the comma must be placed BEFORE the conjunction. The other alternatives place the comma in inappropriate places (after the conjunction and after the personal pronouns).    

Answer 2

B). it was late, so i went to bed.
the comma separates the adverb from the main sentence.