Answer:
The C major scale is the only major scale with zero sharps or flats; therefore, no key signature is necessary at all.
The answer is true. Accidentals are a note or pitch that is not part of the key signature that you're playing in, and these notes are marked by using the sharp (♯), flat (♭), or natural (♮) signs. Accidentals change the note they accompany either by raising or lowering it by a semitone (or half step).
