4. He rushed back to take a picture. The rainbow had gone. a. He rushed back to take a picture, so the rainbow had gone.
b. When he rushed back to take a picture, the rainbow had gone.
c. Because he rushed back to take a picture, the rainbow had gone.

b

Explanation:

The others are not correct grammar.

of course not love is   love u cant change it.

well basically since ima beginner people will answer any subject "right away"and if you get more points you could ask more questions or if you answer someone's question you get points