PLEASE HELP What form or rule is demonstrated in this sentence?

The plan was this: divide the troops, surround the enemy, and capture the headquarters.

colon used to divide two clauses
commas between adjectives preceding a noun
colon used before a list of items

Geoffrey is writing a paper investigating friendly-fire incidents in recent us military actions. which paragraph topic would be relevant to his paper and would therefore merit inclusion in his final draft? a) a paragraph criticizing us military actions in the viet nam war b) a paragraph discussing how friendly-fire incidents are investigated c) a paragraph describing what basic boot camp is like for a new army enlistee eliminate d) a paragraph discussing how hard an extended military service can be on a family