Which of these is the largest living Carbon sink? Forest soil, oceans are insects.

The largest living carbon sink among the options you provided is forest soil. Forests and their associated soil contain a significant amount of carbon due to the accumulation of organic matter from dead plant material, tree roots, and other organic substances. Forests play a crucial role in sequestering carbon dioxide from the atmosphere through the process of photosynthesis and storing it within their biomass and soil.