Choose the most appropriate word to fill in the blank. JAPANESE 1A

Kublai khan was successful in which of the following during his time as the great khan? a. he conquered the last of the song dynasty and brought china under mongol rule. b. he completed successful invasions of japan, vietnam, and the korean peninsula. c. he agreed to share power with other khans in order to rule more territory in asia. d. he united the mongol tribes into a single empire and conquered neighboring lands.