What is the main difference between vulnerability testing and penetration testing?

Question $1$Select one:

a$.$

Vulnerability testing attempts to exploit vulnerabilities, while penetration testing simply identifies them.

b$.$

Penetration testing and vulnerability testing do not attempt to exploit vulnerabilities, they only provide recommendations for fixing them.

c$.$

Penetration testing attempts to exploit vulnerabilities, while vulnerability testing simply identifies them.

d$.$

Vulnerability testing and penetration testing are the same thing.