take it or leave it VS willy or nilly

Hello

Which one of the options below is OK?

He will win the race, …

A: take it or leave it.
B: willy or nilly

Many thanks

Neither!

“Take it or leave it” is used to indicate that this is the only offer being made, and if it is not acceptable, then there is no alternative. It cannot be applied to a race. It might be apply to the bookmaker’s odds on the race:
I’m offering odds of 3 to 1 on that race, take it or leave it. (I will not change the odds.)

The term “willy-nilly” NOT “willy or nilly” indicates that something is done in a haphazard way or is done whether the person wishes to or not. It cannot be applied to a race. It might be applied to a style of running:
When he ran his arms flailed about willy-nilly.

You could say- He will win the race come what may. Or - He will win the race regardless.

How about these?
He will win the race, to be sure.
He will win the race, by all means.
He will win the race, won’t he? (though there is no question mark in the post)

‘to be sure’ is okay.
‘won’t he?’ is an appropriate question tag, but changes the emphasis. In the original the speaker is certain. Using a question tag indicates that he is not certain.

‘be all means’ doesn’t work, though ‘by any means’ does, but not with the original meaning. It would indicate that he will stoop at nothing (even cheating) to win.

In the absence of the context ‘by all means’ indicates the mood of the speaker. So does the question tag. All are possible to me like ‘come what may’ and ‘regardless’. The poster has given his own options, after all.

‘By all means’ is an idiom which indicates the speaker is willing for the listener to have/do something.
“Have you finished with the sugar, please?”
“Yes, take it by all means.”
It does not fit in the sentence above.

This is the third post in a row where you have been unable to admit your mistake and have given some nonsensical excuse instead. No one will think any the less of you for making an error. You speak English as a second language at a fantastic level, but sometimes it is not yet as perfect as you would like it to be.

People in glass houses …

Oh, is it a proverb throwing contest?

None so blind…

You are trying to read unwritten pages. Why do you want to assert that what you say is or should be the final? By ‘by all means’ I mean ‘in every possible way’. What is wrong with that here in the absence of the real context? Can’t others express their views? I’m not interested in the wayside English you might recommend. I will consider the views of others and form my own opinion in tune with what is in vogue or what is accepted and recognized where I handle it. So, avoid unnecessary interference in all that you see. You are not a grammarian like those whom I have learned from. I do not understand who you think you are. Pitiable!

LOL!
You do yourself no favours with that attitude.

People in glass houses …

No favours there either.

Glad you got the point.

Whatever.

Thank you teachers for your great help.

How about the idiom? Like it or lump it?

He will win the race Like it or lump it.

He will win the race, like it or lump it.
= whether you are happy with the outcome or not, he will win.
It’s not usually used of a race, because it’s not possible to know a race result ahead of time.