Final answer:
The thymus, spleen, and lymph nodes are critical components of the immune system, supporting adaptive immune responses by producing lymphocytes, filtering blood and lymph, and removing pathogens.
Step-by-step explanation:
When explaining the functions of the thymus, spleen, and lymph nodes, the correct response would be: "These organs support immunity." The thymus gland is responsible for producing T cells or T-lymphocytes, which are crucial for the adaptive immune response. The spleen's primary roles include filtering the blood, removing unwanted or damaged red blood cells, and detecting viruses and bacteria to trigger an immune response. The lymph nodes act as filters for the lymphatic system, removing pathogens and debris from the lymph and also facilitating adaptive immune responses through the action of T cells, B cells, and accessory cells.