What is a disease in which the blood does not clot normally?

The correct answer is Hemophilia.

Hemophilia is a genetic disorder in which the blood does not clot normally due to a deficiency or abnormality of one of the clotting factors, specifically clotting factor VIII (hemophilia A) or clotting factor IX (hemophilia B). Individuals with hemophilia have prolonged bleeding times and experience difficulty in stopping bleeding after an injury or surgery.