"to complete" vs "to have completed"

[Audiolaik]

Hello,

The builders undertook to ..................... the whole job by the end of the week.

a) to complete
b) to have completed

I do agree that answer "a" is correct; all the same, what about answer "b".

Would it be a mistake if I chose it?

p.s. no context provided, sorry :(

[Mister Micawber]

.
I don't think B works-- at the time they undertook the job, the completion was clearly in the future.
.
_________________
Native English teacher at Mister Micawber's

[Audiolaik]

What about the following:

...The builders undertook that they would have completed.....

Would it be correct?

Thanks!

[Lxguy]

[Mister Micawber]

.
Even worse, in my estimation! Undertook that they would complete is OK.
.
_________________
Native English teacher at Mister Micawber's

[Yankee]