Traditionally, indigenous comes from the Latin word indigena (indu/endo: in/within + gignere: to beget (to procreate or generate). But here we are simply looking at roots. The root words here are -gen (something produced, and by extension, birth) and -ous (possessing/full of), and that combination is not an option, it seems. HOWEVER, it is not uncommon for suffixes to have more than one meaning, and this is no exception. -ous also means 'having, full of, or characterized by', meaning your answer is the second option, 'the word root “gen” means “birth,” and the suffix “-ous” means “having the quality of something.”'
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".
The Correct Answer Should Be - John Muir's "Save The Redwoods" presents facts and evidence to convince readers to rescue the Sequoia.
I Hope This Helps You!! :D