Question

Which of the following sentences is grammatically correct?

I was late to dinner there was a traffic jam.
I was late to dinner, there was a traffic jam.
I was late to dinner; there was a traffic jam.
I was late to dinner for the traffic jam.

Answer 1

the answer is the second one

Answer 2

The correct answer is the second option.

This option correctly uses a comma to connect what would be two independent sentences.
The first sentence is a run-on, and the fourth does not correctly or clearly state the "problem" in the sentence. The third option uses a semicolon which is not necessary in this sentence.