Which of the following sentences contains an infinitive? OA. Courtney traveled to the mountains each year for a ski trip with her family.
OB. My best friend led the class in singing "Happy Birthday" to our teacher.
OC.
Rick promised to listen to his aunt while he was visiting her for a week.
OD.
Komail practiced playing his guitar to his animals before each big recital.

the president was the speaker and it was a great part of history.

explanation:

video of the national aeronautic space administration's (nasa) coverage of president john f. kennedy’s address at rice university, houston, texas, concerning the nation's efforts in space exploration. in his speech the president discusses the necessity for the united states to become an international leader in space exploration and famously states, "we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard."

what is   the question

i have a basic answer but if you want a more in depth

reflexive.the third one.