Which statement about converter dollies is correct?

Answer: C — Sometimes do not have antilock brakes

Converter dollies sit between two trailers to form doubles or triples, and their braking setup has varied over time. Not all converter dollies come with ABS, especially older models, so you can encounter units that lack antilock brakes. That variability is why the statement about sometimes not having ABS is correct. The other options don’t fit as well. ABS isn’t guaranteed on every converter dolly, so saying they always have ABS isn’t accurate. Special licenses aren’t required just for operating a converter dolly as part of a doubles/triples combination—you use the standard CDL with the appropriate endorsements. And the dolly’s brakes aren’t powered by the trailer brakes; the dolly’s braking system is linked to the vehicle’s air brake system, not driven directly by the trailer brakes.