3. You are testing a PIN validator, which accepts valid PINs and rejects invalid PINs. A PIN is a sequence of digits. A PIN is valid if it consists of four digits, at least two of which are different. You have identified the following valid equivalence partitions:

Variable: PIN code length

• The partition “length correct”                     – four-digit PINs
• The partition “length incorrect” – PINs with length other than 4

Variable: Number of different digits

• The partition “number of different digits correct”               – PINs with at least two different digits
• The partition “number of different digits incorrect”           – PINs with all digits being the same

Which of the following is a MINIMUM set of input test data that covers all identified equivalence partitions?