Which of the following is a ceremony, without the performance of which, a Hindu marriage is considered…

Section 7 of the Hindu Marriage Act, 1955 allows a Hindu marriage to be solemnised according to the customary rites and ceremonies of either party. Saptapadi is essential, and completes the marriage when the seventh step is taken, only where those customary rites include it (section 7(2)). Kanyadaan and sindoor-daan are not universal statutory requirements either. So none of the listed ceremonies is required for every Hindu marriage.