Which method is also known as Fusion, using an adhesive agent to attach hair?

The method known as Fusion involves using an adhesive agent to attach hair extensions to natural hair, making "Bonding" the correct answer. In this technique, an adhesive is applied to small sections of hair, where the extensions are then attached. This method creates a seamless blend and can provide a natural look, as the extensions are fused to the natural hair at the roots.

In contrast, the other choices involve different techniques for adding or manipulating hair without the use of adhesives. Weaving typically involves sewing extensions onto natural hair, while braiding is a technique that intertwines natural hair to create a specific look or hold extensions in place. Pinning is often a temporary solution used to secure hair rather than a method of attaching extensions with lasting results. Therefore, Fusion or Bonding is distinct for its innovative use of adhesive to achieve a more permanent and integrated result.