Which of the following techniques does a vulnerability scanner use in order to detect a vulnerability on a target service?

Port scanning identifies open ports and running services but does not itself determine whether a vulnerability exists on those services.

Banner grabbing retrieves service version information and is a preliminary reconnaissance step, but it is not the mechanism by which vulnerabilities are confirmed.

Injecting arbitrary data describes fuzzing or active exploitation techniques used in penetration testing, not the standard passive detection approach of vulnerability scanners.

Analyzing service responses is the core detection mechanism of a vulnerability scanner - it sends specific requests and compares responses against a database of known vulnerable behaviors, error messages, or version indicators. This allows the scanner to identify whether a service is susceptible to a known CVE without necessarily exploiting it. The response analysis differentiates a vulnerability scanner from simpler reconnaissance tools.