The original question goes:
I ______ to see my grandma and help her with some housework every week.
B. am going come
D. will come
The given answer is D. However I think C is possible too.
When I was studying the present tense, my English teacher told us that "if you describe an event that will happen regularly, then you should use present tense". For instance, "I go hiking every week".
My understanding of this question and the answer is, that the speaker might be giving a promise for the future. Like he didn't come to see her grandma regularly before, but in the future he will come to see her grandma every week regularly.
But if he's describing an event that's already happening regularly? In that case, shouldn't the answer be C?
Am I wrong OR are the question & the answer wrong?