A vessel engaged in a towing operation that severely restricts both the towing vessel and her tow in their ability to deviate from their course must exhibit, in addition to the RAM lights and shapes, the lights or shapes prescribed in which Rule?

Why A is correct

33 CFR §83.27(c) states that a vessel engaged in a towing operation which severely restricts the towing vessel and her tow in their ability to deviate from their course shall, in addition to the RAM lights or shapes, exhibit the lights or shapes prescribed in Rule 24 (§83.24), which covers towing and pushing vessels.