(1) In order to be entitled to retain its class D authority, on or before March 31st of each year, every class D carrier must submit with its annual report to the commission one of the following concerning its operations for the previous calendar year:

(a) A report on a form available from the commission office showing that the carrier's class D service was used by at least 20 customers per month during each month of the preceding calendar year,

(b) A report on a form available from the commission office showing that the carrier's class D service generated at least $5,000 gross revenue for the preceding calendar year, or

(c) A signed and verified statement as described in ARM 38.3.1204.