Answer:

A. key of C

C major

In C major, there are no sharps or flats in the key signature, just as there are no sharps or flats in the C major scale. In keys other than C major, the key signature is written to the right of the clef, just before the time signature, at the beginning of each line of music.

Hope its help

Answer:

A. key of C

what key signature has no sharps nor flats written before the time signature