Question

Refer to the passage.

"The Chams from the time of King Wen knew the art of fortification. They protected their cities with walls in brick. The citadels and strong places served as depots for materials of war.

The Cham subjects helped the officials by giving forced labor and service to the king. The landlords gave a tax in kind which was measured by jak, a measure of whose value we are quite ignorant. Half of this tax went to the landlord and the other half to the king, except in the case where the latter had made a gift of it to the temples or monasteries. We find the kings always busy making grants to temples or monasteries.”

Excerpts from The Indian Colony of Champa, which describes Champa between 200 CE and 1400 CE in present-day Vietnam; published by Phanindranath Bose in 1926

Which of the following best explains the Mongolian khans’ difficulty with bringing Vietnam under the Pax Mongolica?

The policy of defense and fortification to prepare villages and cities for times of war
The policy of nonviolent resistance and diplomatic negotiation, supported by Hindu religious leaders
The policy of establishing strong trade ties with the Yuan dynasty to deter a conquering force
The policy of forced labor to quickly establish a conscripted army when facing attack