Which sentence uses the correct form of interesting to make a comparison?

that's the most interestingest book i've ever read.

that's the most interesting book i've ever read.

that's the interestingest book i've ever read.

that's the more interesting book i've ever read.

That's the most interesting book I've ever read. (second option)

Explanation:

The sentence requires the superlative degree of the adjective describing the noun 'book'.

The adjective interesting forms its superlative degree by placing 'most' before the positive form: the most interesting.

the climax is the highest peaking point of the movie it is mostly near the end of the movie where the main characters point of view changes. it is the most excting action part of the movie