Help ;-;
Which group of words is a gerund phrase?
"It is important to seal windows and doors properly to prevent heat or cold from escaping through gaps."
A. It is important
B. windows and doors
C. to prevent heat or cold
D. escaping through gaps

Delegates: representatives who cast votes at a political party's national convention. binding: if a primary or caucus is “binding” that means the delegates won in that contest are legally bound to vote for a particular candidate at the parties national convention.a primary is a preliminary election used to determine a party's nominee for a specific office. the winner of the party's caucus, or primary, wins the party nomination for that state. then the delegates meet at their party's national party convention, which is a formal gathering of all party delegates from all states.