Why did japan enter world war i on the allied forces' side?

a. it had a previous treaty of alliance established with england.
b. it was angered when germany began sinking its ships in neutral water.
c. it disagreed with the german action of invading neutral belgium.
d. it was an ally of austria and joined after the archduke was assassinated.

Me! these questions are based on american people in the south essential questions: question 1: for what reasons will one group of people exploit another?focus questions: question 1: what influenced the development of the south more: geography, economy, or slavery?question 2: what were the economic, political and social arguments for and againsts slavery in the first half of the 19th century.