4. Volunteers collect money and nonperishable food for the Food Pantry, a nongovernmental VHWO, by going house to house once each year for donations. The services of the volunteers should be accounted for as follows:

a The fair value of the service is estimated and recorded as contributions that increase unrestricted net assets.

b The fair value of the service is estimated and recorded as contributions that increase either unrestricted net assets or temporarily restricted net assets, depending on donor-imposed restrictions on the resources collected.

c The per diem wage rates of the donors are recorded in unrestricted net assets.

d None of the above