The 12-bar blues is which of the following? a) a chord progression b) a famous ballad example c) a traditional tempo d) a melody used in hymns

the answer is A i believe '' a chord progression ''

A, a chord progression.

Explanation: The 12-bar blues is, as his name tells us, the blues conformed with 12 bars.

the chords used are I, IV and V, and the use of them may change depending on the blues.

The most classical example is:

I   -   I  - I - I

IV - IV - I - I

V  - IV - I - I

So the right answer is A, a chord progression