The Harappans made A. Seals out of stone B. Pots with yellow designs C. Spindle whorls made of iron D. Gold vessels

The Harappans made seals out of stone (steatite), and they also made vessels and ornaments of gold. They made pottery with black/red designs, not yellow. They did not use iron — iron was unknown during the Harappan civilization (Bronze Age). Hence A and D are correct.