What the butt is MyProgramming lab asking me to do?

[masonmoore93]

The problem states: "Assume that credits is an int variable whose value is 0 or positive. Write an expression whose value is "freshman" or "sophomore" or "junior" or "senior" based on the value of credits. In particular: if the value of credits is less than 30 the expression's value is "freshman"; 30-59 would be a "sophomore", 60-89 would be "junior" and 90 or more would be a "senior"."

I see that it's asking for an expression, but I have no idea what it wants me to put. The code I've found that works when assigning a value to "credits" is:

credits = 3

if credits <= 30:
    print("freshman")

elif credits >= 89:
    print("senior")


elif credits >= 60:
    print("junior")

elif credits >= 30:
    print ("sophomore")

>>> freshman

But MyPLab states that this is wrong. What the butt does it want from me