To answer this question, we need to understand the difference between "it's" and "its."
Option A) It's - This option is correct. "It's" is a contraction of "it is" or "it has." In this context, "It's going to rain soon" means "It is going to rain soon."
Option B) Its - This option is incorrect. "Its" is a possessive pronoun used to show ownership. For example, "The dog wagged its tail."
Option C) None of the above - This option is incorrect because option A is correct.
Option D) 1 or 2 both are correct - This option is incorrect because only option A is correct.
The correct answer is A) It's. This option is correct because "It's" is the contraction of "it is" and is used to indicate that something is going to happen.