What does a main idea do?

a. show what readers do not know
b. state what the story is about
c. summarize details and events
d. state the ultimate conclusion

in "people in peace, not profit and war" chrisholm uses inductive reasoning for her argument against defense spending by stating that the new administration, like most americans, wanted to invest in social objectives, so they must not want to prioritize defense spending. mr. nixon said "we can delay no longer in launching new approaches to the problem that beset them", but chrisholm points out that the programs were delayed anyways.

i think the answer is either c or d

im thinking d might make more sense though

sorry if im wrong