Answer:
The correct answer is option d. "The promotion of the merchant class".
Explanation:
The Heian period (from 794 to 1185) was the last part of classical Japanese history. During this period Japan implemented many ideas from China, however the promotion of the merchant class was not one of them. The merchant class was implemented in Japan much later in history, particularly, during the Edo period that lasted from 1603 to 1867.