what is the difference between 'delayed', 'postpone', and 'put off'?

[rebecca]

HELLO,
7. The plane was ________ by two hours because of bad weather.
(A) delayed
(B) postponed
(C) put off
(D) rearranged
In this question, what is the difference between 'delayed', 'postpone', and 'put off' ?
Thank you very much!
_________________
I love everyone here!

[Mister Micawber]

.
The plane was delayed; the flight was delayed or postponed or put off-- but really, we only use 'delayed' for air travel. In addition, 'delayed' could mean merely that the plane has been slowed en route, while postponed/put off could only mean that its departure was rescheduled.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber