Answer:
If we go to the movie, then I will have popcorn.
Step-by-step explanation:
Conditional mood is a mood in grammar, in which we find certain type of condition. In this mood happening of a certain event depends on happening of an other event.
According to the definition provided, the sentence that is reflecting a conditional mood is the third one.
In the given sentence the condition that appeared is: 'having popcorn' is dependent on their 'going for a movie'.