In which sentence is the agreement between the pronoun and antecedent correct? Every school of architecture sets their own specific requirements. Each architecture student must plan their high school and college courses carefully. Art and math are courses architecture students must have on their schedules.

The third option is correct: "Art and math are courses architecture students must have on their schedules."

The other two uses the word "their" when referring to a single thing/person. The correct word should be: "Each architecture student must plan his/her high school and college courses carefully." and "Every school of architecture sets its own specific requirements."