An article problem

[SARDORBEK]

Dear ALAN!

In my country, English is taught as a foreign language and students are given tests to pass the exam. Four answers are given and only one answer is usually correct in the testing examinations.
As we learn EFL, sometimes even test producers also make mistakes by putting two equal
correct answers in question, I think.
Here is the question that has always confused me:

Would you rather live in … town or in … country?

a) -/the
b) a/the
c) the/-
d) the/the

Which one is correct?

However, I found this sentence in two grammar books the other day:
In “English Grammar in Use” (2-edition) (by the way, most questions are based on this book,
so is this question)
it is given as follows:

Would you rather live in a town or in the country?

while in “Practical English Usage” (by M. Swan)
it is given as follows:

Would you rather live in the town or in the country?

Thus, two answers are correct ---- > 'b' and 'd', aren't they?
(And as for “a”, as there is the expression – “in town” that we have across
many times, please,could YOU give an explanation on this point at the end)

What is the difference between the two (b;d) sentences?
Are both of them correct separately?
Which answer is more correct in the test?
If I have to find the correct answer, which answer should I mark after all?

Dear TEACHER!
Please, could YOU give me a clear explanation?
Sincerely,
SardorBEK

[Alan]

(b) is the most idiomatic, but only (c) would be unacceptable.

With, therefore, 3 grammatically possible and meaningful answers, this would be an exceptionally poorly thought-out test question!