When calculating the service size for a single-family dwelling using the standard calculation, what part of the total general lighting and small appliance loads must be calculated at $100 \%$ ?
a. First $3,000 \mathrm{VA}$
b. First $10,000 \mathrm{VA}$
c. First $15,000 \mathrm{VA}$
d. First 30,000VA