Bones of a horse have been reported from which Harappan site?

Horse bones have been reported from Surkotada in Gujarat. Their identification has been debated by scholars, so the answer should be understood as the standard archaeological-report and examination convention, not as proof that the horse was common throughout Harappan society. Thus the other options either belong to a different archaeological site, represent a different period, or do not match the specific evidence asked in the question.