How did the death of Mary Queen of Scots contribute to a holy war between England and Spain?

The southern colonies practiced indentured servitude and slavery because cash crops such as tobacco and sugar required many workers. the fishing and shipping industries required many workers. imprisoned debtors were brought from africa to settle the colonies. indentured servitude and slavery were not allowed in the caribbean colonies.

Which of the following is not critical in decision making? a. taking action independentlyb. considering internal factorsc. considering external factorsd. considering decision consequences

This is for my social studies guide and i can answer 21/22 of it perfectly fine. but can someone tell me what the caste system was, and what divisions/classes that it was apart of it?