4. Suppose the variable x represents students, y represents courses, and T (x, y) means "x is takinjg y ". Match the English statement with ALL its equivalent symbolic statements in this list (i.e. Fill in the blank all number that represents the English sentence) NOTE: If nothing matches, write NONE. 9yaT (x, y) a. Every course is being taken by at least one student b. There is a course that all students are taking. c. Some students are taking no courses. d. No course is being taken by all student e. No student is taking any course