Computers connected to the Internet are more vulnerable when linked through which method?

When evaluating the vulnerability of computers connected to the Internet based on their connection methods, it's essential to consider the security implications of each method. A cable modem offers high-speed Internet access but relies on a shared network, which can expose users to additional risks, particularly if their network is not properly secured. Similarly, a dial-up line, which is slower than other forms of Internet connection, can still present vulnerabilities, particularly due to its potentially outdated security protocols.

The correct answer encompasses both the cable modem and dial-up line methods, emphasizing that both present significant security concerns. Cable modems can expose multiple users to the same network vulnerabilities, while dial-up lines may lack robust encryption and security measures commonly found in more modern connection methods. This aspect of shared connections and the inherent weaknesses in older technology makes both options less secure than other contemporary Internet connectivity methods. Therefore, linking computers through either a cable modem or a dial-up line increases their vulnerability to threats from the Internet.