Correct Answer: it rains

Solution : The correct choice is the second option , i.e., it rains .

Explanation :

In conditional sentences, especially those using "if," the present simple tense is often used to refer to general truths or facts.

In this sentence, "it rains" is a present simple tense, and it fits well with the structure of a conditional sentence. It conveys the idea that the speaker will not go out in the event of rain.

Other Options:

1. raining: The original phrase is "if it is raining", which is grammatically incorrect. It should be "if it is raining".

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2. will rain: This option changes the tense and doesn't fit well in the structure of the sentence. The correct form is needed for present-tense conditions.

3. rained: This option is in the past tense and is not suitable for a present tense condition.

So, the correct sentence would be: "I will not go out if it rains."