Final answer:
David should obtain professional liability insurance (E&O insurance) and general liability insurance.
Step-by-step explanation:
As a real estate salesperson, David should obtain professional liability insurance, also known as errors and omissions (E&O) insurance.
This insurance protects David from potential lawsuits if a mistake or negligence on his part causes financial harm to a client. Additionally, David may also consider obtaining general liability insurance, which provides coverage for bodily injury, property damage, and personal injury claims that may arise during the course of his work.