The correct answer is C) a towing connection. Inflatable liferafts are required to be equipped with a towing connection, which allows the liferaft to be towed by a rescue vessel if needed. This is a critical safety feature that enables the liferaft to be maneuvered and easily retrieved in the event of an emergency. The other options are incorrect because inflatable liferafts are not typically equipped with a portable radio, canned milk, or an oil lantern. These items may be part of the safety equipment kit in the liferaft, but they are not considered mandatory components of the liferaft itself.