Climax?

There are many points in this novel where someone could think that it is a climax, there is the part where Lennie kills Curley's Wife or when George shoots Lennie.  Both of these are plausable suggestions however I would have to go along with with when Lennie kills Curley's Wife, because I considered George shooting Lennie as a falling action/resolution.  So what this post is asking is what do YOU think is the climax and why?