I don't have the book so I can't give a line of evidence but Atticus was all about teaching Jem and Scout those little life lessons without them even noticing so this instance was one of those little lessons he gives them. Hope this helps :)
If I were you I would use direct quotes from the book or whatever you are reading. Direct quotes give evidence from the text and prove points. You may also use line numbers if instructed by your teachers.
An irregular verb is a verb that does not have regular forms, that is forms formed by stem+ed, such as for example:
Walk+ed: the regular past tense of walk is walked.
Here the irregular verb is "go" - the correct answer is D. I go, I went, I will go.
The other options show regular verbs.
B) Tubman was buried with full military honors