From where is lymph derived?

Lymph is derived from tissue fluid that surrounds cells, which seeps out of the capillaries into the surrounding interstitial space after nutrient and gas exchange has occurred. This interstitial fluid contains various substances, including proteins, waste products, and immune cells.

Once this fluid accumulates in the interstitial spaces, it enters the lymphatic vessels, where it is known as lymph. The lymphatic system plays a crucial role in maintaining fluid balance in the body and is instrumental in the immune response. Thus, the correct choice highlights the origin of lymph as a modified form of the tissue fluid that bathes the cells in our body. Other options pertain more specifically to other biological processes or components rather than directly indicating the source of lymph.