Friends at A Smokey Izakaya

From Twitter

Clerk: I __ go. I __ get up early; I’m __ to meet my boss early–and, I __ stop drinking, eating so much pork.

Clerk’s Foreign Friend (a vegetarian wearing a gas mask who sipped one beer all night): Cool.

① must
② have to
③ supposed to
④ should

Answers And Explanation:
I have to go. (Answer 2) Have to shows obligation.
I should get up early; (Answer 4) Should shows obligations we want to resist
I’m supposed to meet my boss early (Answer 3) Supposed to precedes obligations others are expecting.
–and, I must stop drinking, eating so much pork. (Answer 1) Must introduces intentions or obligations with moral- or beneficial- imperatives.