Which term refers to yarn that is made from only the long fibers of the flax plant?

The correct term for yarn that is made exclusively from the long fibers of the flax plant is linen. Linen is known for its strength and durability, qualities that make it a popular choice for various apparel and textile products. The fibers derived from the flax plant are processed to create linen yarn, which has a unique texture and is often characterized by its breathability and moisture-wicking properties.

Satin refers to a type of weave that creates a glossy surface but is not a fiber itself. Line is a term that can refer to a specific type of finished textile product or garment line but does not relate to yarn made from flax. Cotton, while also a significant textile fiber derived from the cotton plant, is distinct from linen and comes from a completely different plant source. Thus, linen is the specific term that accurately describes yarn produced from the long fibers of the flax plant.