Final answer:
The wife of Guru Har Rai Ji was Mata Krishan Kaur (Option A). Their marriage is an example of the important role women played during the era of the Sikh Gurus.
Step-by-step explanation:
The wife of Guru Har Rai Ji, the seventh Guru of Sikhism, was Mata Krishan Kaur. In the multiple choice question provided, the correct option is A) Krishan Kaur. Guru Har Rai Ji's marriage to Mata Krishan Kaur highlights the customs and traditions prevalent during the time of the Sikh Gurus, and it reflects the significant roles that women played in supporting the Sikh community and its leaders.