Why did marco polo state that it is not easy for him to describe hangzhou in writing? a) he was afraid that if he did not describe it accurately that kublai kahn would become angry with him. b) he did not speak chinese and was unsure if he was misunderstood the amount of trade and sales that took place. c) he feared that other merchants in europe would find out about the wealth in china and he would lose his position. d) he was amazed by the amount of commerce and trade in hangzhou because he had never seen a city that could compare.