A nurse in an outpatient facility is reinforcing teaching to a client about the development of mental illness. Which of the following statements by the nurse describes the role of a vulnerability gene?

"It is a gene variant that determines an individual's likelihood of recovering from mental illness."

"It is a gene variant that increases the risk for development of a specific mental illness."

"It is a gene variant that is responsible for an individual's resilience to stress."

"It is a gene variant that is responsible for the development of a specific mental illness."