COULD I TELL I WHAT I BRAILLE ALPHABET / USED I IS /

69. Could I tell I what I Braille alphabet / used I is /?

A. Could you tell me what Braille alphabet is used for?

B. Could you tell me what the Braille alphabet is used?

C. Could you tell me what the Braille alphabet is used for?

D. Could you tell me what the Braille alphabet used for?