Concept:An entrepreneur is someone who establishes a business by assembling resources and bears the associated risks.
Explanation:A sole proprietor is the single owner of an unincorporated business.
This person directly sources for funds and other resources needed to start and run the enterprise.
He or she makes major decisions, assumes all financial risks, and keeps all profits.
These actions strongly match the definition of an entrepreneur.
A board member only guides policies and may not bear personal financial risk.
A debenture holder is a lender, not a business owner.
A bank manager manages a financial institution on behalf of its owners.
Thus, among the options, a sole proprietor clearly acts as an entrepreneur.
Answer:D. sole proprietor