I'll give you a question, please answer with step-by-step reasoning process.
Making a schedule was easy to pick, the major called for knowledge that required a certain what?\nOptions:\n- color\n- class\n- meeting\n- university\n- encyclopedia

class
Class means a group of students or pupils who are taught together.

Making a schedule was easy to pick, the major called for knowledge that required a certain class.

.

So, the answer is class