Input: I do this task because it is boring.
(A) Because I used a preposition as important information I can write and do pretty much anything I want and it is not boring at all.
(B)People do not like doing boring things and if and when they do them it is despite of them being boring and not because of it.
(C)It is very boring to think about boredom and I used the word do and have to include it because otherwise it will not be correct.
Output: B