Under 33 CFR §164.25, within what time period before getting underway on navigable waters of the United States must the required equipment tests be completed?

Why C is correct

33 CFR §164.25(a) requires that the listed equipment—including primary and secondary steering gear, internal communications, emergency generator, storage batteries, and main propulsion machinery—be tested no more than 12 hours before entering or getting underway. The 48-hour figure in §164.25(d) applies specifically to the emergency steering drill, not the general equipment tests.