Why Did the Spanish Establish Missions in California

Why did the Spanish establish missions in California?

A) They were intended to serve as places of religious conversion and economic productivity.
B) They were vehicles that could preserve Native American language and culture.
C) They were institutions where the Spanish studied Native American religions.
D) They were outposts to help attract Native American emigration to Spain.
E) They were churches that only the Spanish were allowed to use.