SBI PO 22 Nov 2021 Shift 1 Paper

Select the phrase\connector from the given three options which can be used to form a single sentence from the two sentences given below, implying the same as expressed in the statement sentence.
I was not in a situation to step out of the house yesterday because of my severe headache. I attended the sales meeting at my office on the instructions of my senior management.
I. Since
II. Notwithstanding
III. Still