Which items are used to absorb energy during the tow?

The correct option, towing hawsers, serves as the appropriate choice because these are specifically designed ropes that are used for towing vessels. Towing hawsers are usually constructed to absorb shock loads which occur during the towing process. This energy absorption is crucial, as it helps to prevent sudden shocks that could otherwise damage both the towing vessel and the vessel being towed. Their composition can include materials that provide elasticity, which is advantageous during operations in varying sea conditions, allowing for more controlled towing.

In contrast, the other items listed do not have the same energy absorption characteristics in the context of towing. Tow ropes, while they can be used for various functions, might not always be designed to absorb energy effectively for towing purposes. Anchor chains are primarily used to hold a vessel in place and do not facilitate towing. Deck lines, typically employed for securing or handling lines on deck, lack the necessary strength and design for energy absorption during towing operations.