888 - Logical Reasoning

Question: Bill earns more commission than does Sandra. But since Andrew earns more commission than does Lisa, it follows that Bill earns more commission than does Lisa.
Any of the following, if introduced into the argument as an additional premise, makes the argument above logically correct EXCEPT:

1. Andrew earns more commission than Bill
2. Sandra earns more commission than Lisa
3. Sandra earns more commission than Andrew
4. Sandra and Andrew earn the same amount of commission
5. Bill and Andrew earn the same amount of commission