As manager and team leader, Sandra calls her subordinates together and says, "Okay, this week I’ll need each of you to work a few extra hours because we need to get out those brochures that were back-ordered." She is exercising her power.

A) legitimate

Explanation:

Legitimate power is the formal authority that a person has by virtue of being in a certain position in a company or chain of command and that position having certain vested powers in it. For instance, the CEO of a company has the legitimate power over every employee in the Organization and as such can order them to fulfil certain actions.

Sandra as manager and team leader has this power over her subordinates and as such can order/ formally request them to work longer if necessary to meet company obligations.

I believe the answer is: the article "Peach Trees" on a local university website

A source would be considered to be reliable if it's written by someone who had some sort expertise in relevant field. Article on local university website would be most likely to be written by either a student who study the subject or the professor who already considered an expert at the subject.