<human>: Does "Norbu states that the Ming dynasty, preoccupied with the Mongol threat to the north, could not spare additional armed forces to enforce or back up their claim of sovereignty over Tibet; instead, they relied on "Confucian instruments of tribute relations" of heaping unlimited number of titles and gifts on Tibetan lamas through acts of diplomacy." correctly answer the question of Where were the Mongols trying to raise?
OPTIONS:
- yes
- no
<bot>: no