Riddle

Taken from a mine and then locked up in a wooden case. Never released but used by students everyday. What am I?

Choose an answer

A.Chalk
B.Ink
C.Charcoal
D.Lead
Hint: It's a word with 4 letters, starting with "L".

Answer

Lead

Why this is the answer

Pencil 'lead' (actually graphite) is mined from the earth, encased in a wooden pencil, and used daily by students.

This riddle is filed under "What Am I?" Riddles and rated Medium.