Which of the following statements accurately define Preiser's disease?
A. An avascular necrosis of the lunate bone.
B. A degenerative condition of the triangular fibrocartilage complex.
C. A degeneration of the terminal branch of the ulnar nerve in the hand.
D. An avascular necrosis of the scaphoid bone.
E. A tenosynovitis involving the flexor digitorum superficialis.