Deck fittings permit easy handling of lines and reduce ______________ and friction on lines.

Deck fittings are designed to facilitate the efficient management of lines, such as mooring or towing lines. By allowing for smooth interaction between the lines and the fittings, these installations significantly reduce wear on the lines. Over time, constant rubbing against rough surfaces or improper angles can cause lines to fray and deteriorate. The role of deck fittings is to minimize these detrimental effects by providing a cleaner, more controlled route for the lines, thus extending their lifespan.

The other options, while relevant to sailing and line handling, do not directly fit the context of what deck fittings specifically aim to address. For instance, tension refers to the pulling force on the lines, which is more about the nature of the load rather than the functionality of the fittings themselves. Similarly, length and weight do not relate directly to how deck fittings impact the handling of lines in a way that would reduce wear.