Which is the answer according to the passage?
Many teenagers like electronic games so much that they can’t stop playing .They spend hours tightly holding the joystick controls and constantly pressing buttons marked “fire”. They develop pains on their fingers because of the constant pressure. They play and play so that the pains have no chance to cure properly. The rapid wrist movement required to guide the spaceship across the screen causes another problem: The muscles of the wrist and arm become so inflamed and swollen(充血红肿)that they press against the bones. This condition is what doctors now call “Space Warrior’ s Wrist”.
“Space Warrior’s Wrist” is caused by_______.
A. constantly pressing the buttons
B. rapidly moving across the screen
C. tightly holding the joystick controls
D. inflamed and swollen muscles of the wrist