The correct option is c.
Oedema is a build-up of fluid in the body which causes the affected tissue to become swollen. The swelling can occur in one particular part of the body or may be more general, depending on the cause. It is an abnormal accumulation of fluid. The fluid builds up and gets trapped in the tissues around the leaking blood vessels. Oedema can happen in any part of the body. It can be caused by eating too much salt, not moving for long periods, pregnancy or even by side effects of some medicines. Oedema can also be a sign of serious disease.