Had it not rained, it wouldn’t have been so bad
- It was so bad because it didn't rain
- it rained and so it wasn't bad
- it wasn't bad because it rained
-
it rained and that made it so bad
The correct answer is: D
Explanation
The usage of the anomalous verb 'had' alongside with the negatives; 'not' and that in 'wouldn't' means that, it actually rained and that didn't make things good.
There is an explanation video available .