"under no account" vs "on no account"

[Hoamuahe]

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #649 "Prepositional Phrases - In, On, Out and Under (22)", question 9

We are going to turn him in to the police. ......... no account will someone get away with stealing from this company just because we are afraid of some bad publicity.

(a) In
(b) On
(c) Out
(d) Under

English Language Proficiency Tests, Advanced Level

ESL/EFL Test #649 "Prepositional Phrases - In, On, Out and Under (22)", answer 9

We are going to turn him in to the police. Under no account will someone get away with stealing from this company just because we are afraid of some bad publicity.

Correct answer: (d) Under
_________________________

Hi, My kind teachers:
Could you tell me why:"under no account" is used here instead of "on no account"?. I looked up in cambridge dic., only on no account is explained.

[Mister Micawber]

It seems to be an error in our input, Hoamuahe. Thank you for letting us know. We will fix the answer sheet.
_________________
Native English teacher at Mister Micawber's