The correct option is A Synovial fluid
Synovial fluid is a viscous fluid found in the cavities of synovial joints. With its egg white–like consistency, the principal role of synovial fluid is to reduce friction between the articular surfaces of synovial joints during movement.
Pleural fluid - Pleural fluid is the fluid that is found between the layers of the pleura, the membranes that line the thoracic cavity and surround the lungs.
Lymphatic fluid - contains infection-fighting white blood cells, which circulates throughout the body.
Peritoneal Fluid - is a liquid made in the abdominal cavity which lubricates the surface of tissue that lines the abdominal wall and pelvic cavity