Put one over on him? Is that an idiom or a phrasal verb?

[Heinz]

English Language Tests, Intermediate level

ESL/EFL Test #293 "English Slang Idioms (15)", question 6

Bryan knew that his partner was trying to put one ......... on him so he quickly dissolved the partnership.

(a) over
(b) under
(c) new
(d) away

English Language Tests, Intermediate level

ESL/EFL Test #293 "English Slang Idioms (15)", answer 6

Bryan knew that his partner was trying to put one over on him so he quickly dissolved the partnership.

Correct answer: (a) over
_________________________

why not under or other why over?

Heinz

[Mister Micawber]

.
It is an idiomatic phrasal verb. To put one over = to fool, trick, unfairly deceive.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber