I'm having difficulty with this sentence:
Tense appears inconsistent to me. I need help understanding the correct use of verb forms.
冬休みにずっと九州に [Fill in the blank] おばあさんのうちにいました(past)
住む
住んだ
住んでいる (Correct)(non-past)
住んでいた
Based on the bold portion above, I would choose option 2 or 4 for tense consistency. But I'm wrong and I don't know why.