Answer:
3
Step-by-step explanation:
"____ est-ce que tu vas" translates to "....are you doing"
1. "qui est-ce" means "who is" so that doesn't fit
2. "que" means "what" which doesn't fit
3. "comment" means "how" which does make sense
4. "que" means "what" (like 2.) so that doesn't fit either