The correct active/passive form of the given sentence is **He asked me if I was coming for the school picnic.

The sentence is in the simple present tense, which is used to describe an action that happens regularly or now. The active voice of the sentence is formed by putting the subject of the sentence before the verb and removing the word "by." In this case, the subject of the sentence is "he" and the verb is "ask." So, the active form of the sentence is "He asked me if I was coming for the school picnic."

The other options are incorrect because:

• He says to me, “Are you coming for the school picnic.” This is the original sentence in the active voice.
• He tells me if I am coming for the school picnic.” This is incorrect because the verb "tell" is used to convey information, not to ask a question.
• He asks me if I am coming for the school picnic.” This is correct, but it is not the most concise form of the sentence.
• He asked me if I was coming for the school picnic.” This is the correct form of the sentence, but it is in the past tense.