I would say the rising action but since that is not in there I think that it is the climax.

In a typical story, the conflict is usually introduced in the

climax

exposition

falling action

resolution

i

Exposition. for example, in romeo and juliet you learn about the feud between the montagues and the capulets at the very beginning. the exposition provides the rising action, so no conflict = no action. that means the conflict has to be introduced before the rising action, which would mean it is in the exposition