The organic act of 1890 defined oklahoma territory and the boundaries of indian territory. what role did it play in deciding the fate of the state of sequoyah?

The Organic Act did not formally recognize Indian Territory.

An Organic Act is the name given to a statute utilized by the United States Congress to describe a territory, in anticipation of being admitted to the Union as a state.  

The Organic Act created Oklahoma Territory, and Indian Territory that were Organized incorporated territories of the United States out of the old "unorganized" Indian Territory.

yup! you are correct it is b.