Apositive or negative outcome of a decision or action can be called a
a. boon
b. consequence
c. tragedy
d. advantage

The best answer here is: Consequence.
A consequence can be both positive and negative, and this is what the question asks for.  Additionally, a consequence is an outcome of an action or decision.

In contrast, option c. Tragedy is only negative, while option d. Advantage is only positive.

Dcalifornia they have the most people with 200+ people per square mile

Ibelive the answer is a