Often people will 'crack' their knuckle by pulling on their pointer finger. The cracking sound comes from knuckle where the finger meets the hand. What's another way to describe this location?

• A. Between the first proximal phalanx and the first metacarpal.
• B. Between the first and second phalanges of the proximal digit.
• C. Between the second proximal phalanx and the second metacarpal.
• D. Between proximal and middle phalanges of the second digit.