Must vs. have to

[John]

Test No. incompl/elem-7 "Modals", question 5

Do you ......... clean the house every day or every week?

(a) must
(b) have
(c) have to

Test No. incompl/elem-7 "Modals", answer 5

Do you have to clean the house every day or every week?

Correct answer: (c) have to
_________________________

As an English teacher, though not British, I disagree with your explanation.

Both "have to" and "must" are of course acceptable here in most English speaking countries.

To make your site more useful, you should probably replace this question with another.

Other than the massive amount of advertising on the website, you seem to be doing a good job. Keep up the good work.

[Yo]

Well, must doesnt make any sense in that sentence, do you must clean the house? I dont think so, have to is the correct answer, are you sure you are an English teacher?