Test Cases 1, 2 and 3 are all valid, because they cover all the possible combinations of conditions and actions in the decision table. Test Case 1 covers the case where the employee is not a car or motorcycle driver, which leads to the action of not allowing the expense claim. Test Case 2 covers the case where the employee drives a diesel car with an engine size greater than 1600cc, which leads to the action of accepting the expense claim at band C.
Test Case 3 covers the case where the employee rides a motorcycle, which leads to the action of accepting the expense claim at band A12.