Which of the following was a negative effect of spanish missions on american indian life?

Many Native Americans converted to Christianity because they thought this was the only way to save themselves from dying from the Europeans' diseases. They also lost their religion. The 'encomienda' system (legalized slavery) also negatorily affected their simple way of life.

Many Native American populations were utterly destroyed by the Europeans' previously unknown diseases long before they ever actually laid eyes on them. Smallpox, chicken pox and the measles were unkown in North America before the Europeans' arrival. 
Thanks to the "Mission System' employed by the Spanish Conquistadores, many Native American religious practices, customs, and uiltimately, languages were lost forever. Many Native Americans were virtually enslaved. Others were outright tricked and killed by the "civilized" intruders.