there are four types of sentences on the basis of their structure
The correct answer is higher!
(alrernatively "more" would also be ok, but not "more high")
The only correct form of comparative for high is "higher".
Rational and logical are quite similar in meaning but rational is something that has logic. These two words are close synonyms and not antonyms.
So you're looking for 2 synonyms. B is the best answer, avert and prevent are synonyms of each other. The other choices are antonyms, or they're at least not synonyms.
Explanation:
while, both, only one, however
