Final answer:
The statement is false because the minimum drinking age is already set by a federal law.
Step-by-step explanation:
The statement that "Bob dirt of a resident of Iowa offers his son money to not drink before 21" is false.
The National Minimum Drinking Age Act of 1984 is a federal law that requires states to set the minimum drinking age at 21 years old in order to receive federal highway funds. Therefore, Bob would not have the authority to offer his son money to not drink before 21 because the legal drinking age is already set by the law.