The correct option is A Go
The type 1 conditional is used to refer to the present or future where the situation is real. The type 1 conditional refers to a possible condition and its probable result. In these sentences the if clause is in the simple present(if you go out), and the main clause is in the simple future(you will get drenched). Hence, Option A is correct. The rest of the options do not adhere to this rule, hence incorrect.