[Grammar] Advervial clauses - as long as, even though, unless

[shanghailuv]

My 2nd question of the day.

While going through exercises, I stuck to the following question:

I will continue to use my bike _______ petrol prices remain high.

a- as long as b- even though c- unless

I went for "b" (even though) but I was scored down.It says "a" is the correct one. I think "a" is grammatically correct and say- I have a lot of money and I am arrogant enough and say - I will continue to use my bike as long as the petrol prices remain high...but this is not the way a person would conceive of a normal conversation or statement. So, "b" should be more along the line of normal conversation.

Please enlighten me.

There is no context but just a question out of hundred others.

 

[Roman55]

I am not a teacher.

If "bike" means bicyle and not motorcyle it wouldn't be normal to say "b" because it doesn't make sense. "a" would be the correct answer.

If it's a motorcyle then "b" would be right, but this seems unlikely.

A meaningful question should not be open to interpretation.