All of the Following Are Considered Exceptions to the General

All of the following are considered exceptions to the general rule that there is no duty to rescue except:

A) Pre-existing duty: For example, lifeguards have signed contracts agreeing to rescue people in exchange for pay and benefits.
B) Witnessing an accident: This creates a duty to step in and help the injured.
C) Employer: A duty exists to help an employee injured while working for that employer.
D) Endangerment: If one puts another in danger, they are obligated to rescue the person put in danger.