lungs, trachea spleen, thymus kidneys, bladder pancreas, pituitary gland
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which organs belong to the lymphatic system?
Possibilities:
- lungs, trachea
- spleen, thymus
- kidneys, bladder
- pancreas, pituitary gland

spleen, thymus