How should the administrator limit the fields available in the customer portal?

Ursa Major Solar would like to expose the custom object SolarPanels to its customer portal. This particular object contains 150 fields, and a majority of the fields are technical codes and internal information.

How should the administrator limit the fields available in the customer portal?
A . Utilize CSS overrides to hide unwanted fields.
B. Create a page variation for the customer portal to hide unwanted fields.
C. Use Field-Level Security to remove access to the unwanted fields.
D. Utilize the Developer Console with coding to hide unwanted fields.

Answer: C