It was raining heavily so they decided _____ outside.

Not to go

Did not go

Do not go

Does not go

It was raining heavily, so they decided not to go outside.

تیز بارش ہو رہی تھی، اس لیے انہوں نے باہر نہ جانے کا فیصلہ کیا۔

This option correctly uses the infinitive form "not to go" to express their decision not to go out due to the weather.