Costs of a workspace in the home for an employee are only deductible when the workspace is:

a$.$

The place where the individual principally performs the duties of the office or employment.

b$.$

All of the choices

c$.$

Used exclusively during the period in respect of which the amount relates for the purpose of earning income from the office or employment and used on a regular and continuous basis for meeting customers or other persons in the ordinary course of performing the duties of the office or employment.