4. The system for selling cinema tickets calculates the discount type based on the client’s birth year (BY) and on th current year (CY) as follows:

Let D be the difference between CY and BY, that is, D = CY – BY

• If D < 0 then print the error message “birth year cannot be greater than current year”
• If 0 ≤ D < 18 then apply the student discount
• If 18 ≤ D < 65      then apply no discount
• If D ≥ 65               then apply the pensioner discount

Your test suite already contains two test cases:

• BY = 1990, CY = 2020,           expected result: no discount
• BY = 2030,           CY = 2029,           expected result: print the error message

Which of the following test data sets should be added to achieve full valid equivalence partitioning coverage for the discount type?