Why is E incorrect?

I did not choose A because of the word "significantly". Why is A correct?

^ can someone explain

Same, also struggling with this one - why is D incorrect? Thank you!

Also, where is the idea of latitude invoked here?

Hi, the whole passage is about explaining a difference in the diversity of species as latitude increases or decreases.

The time theory tells us that the number of species is a function of the time since the last major disruption, so in the absence of another ice age, the poles should have more species in the future. This is a match for A. The theory does not support any info about if future ice ages will happen, or anything about what species have yet to be discovered.