In Reno v. Condon, Attorney General of South Carolina, the case in the book addressing

whether Congress could prohibit states from selling personal information of citizens
without consent, the U.S. Supreme Court ruled that:
a. The Driver’s Privacy Protection Act was a proper exercise of the authority of Congress
to regulate interstate commerce under the First Amendment.
b. The Driver’s Privacy Protection Act was a proper exercise of the authority of Congress
to regulate interstate commerce under the Commerce Clause.
c. The Driver’s Privacy Protection Act was a proper exercise of the authority of Congress
to regulate interstate commerce under the due process clause of the U.S. Constitution.
d. The Driver’s Privacy Protection Act was a proper exercise of the authority of Congress
to regulate interstate commerce under the Regulatory Clause of the U.S. Constitution.
e. The Driver’s Privacy Protection Act was not a proper exercise of the authority of Congress
to regulate interstate commerce under the Commerce Clause.

The correct answer is option b. The U.S. Supreme Court ruled that the Driver's Privacy Protection Act was a proper exercise of the authority of Congress to regulate interstate commerce under the Commerce Clause.

To find the answer to this question, we need to look at the U.S. Supreme Court's ruling in Reno v. Condon, Attorney General of South Carolina. The case addresses whether Congress could prohibit states from selling personal information of citizens without their consent.

To determine the ruling, we can examine the options provided:

a. The Driver's Privacy Protection Act was a proper exercise of the authority of Congress to regulate interstate commerce under the First Amendment.
b. The Driver's Privacy Protection Act was a proper exercise of the authority of Congress to regulate interstate commerce under the Commerce Clause.
c. The Driver's Privacy Protection Act was a proper exercise of the authority of Congress to regulate interstate commerce under the due process clause of the U.S. Constitution.
d. The Driver's Privacy Protection Act was a proper exercise of the authority of Congress to regulate interstate commerce under the Regulatory Clause of the U.S. Constitution.
e. The Driver's Privacy Protection Act was not a proper exercise of the authority of Congress to regulate interstate commerce under the Commerce Clause.

Based on the choices, we can eliminate options (a), (c), and (d) since they mention clauses other than the Commerce Clause.

Now, to find the correct answer between options (b) and (e), we need to refer to the actual ruling in Reno v. Condon. By researching the case or referring to the book that mentions it, we can find the Supreme Court's decision.

Once you have access to the information from the case, you can go through the Supreme Court's ruling to determine the correct answer.

However, as an AI language model, I'm unable to provide real-time access to specific case information or the content of specific books.