What happens with multiple motor unit rotation regarding subthreshold stimulus, threshold stimulus, and maximal stimulus?
a) Subthreshold stimulus increases motor unit recruitment, threshold stimulus recruits additional motor units, maximal stimulus recruits all available motor units
b) Subthreshold stimulus recruits all available motor units, threshold stimulus increases motor unit recruitment, maximal stimulus decreases motor unit recruitment
c) Subthreshold stimulus recruits additional motor units, threshold stimulus decreases motor unit recruitment, maximal stimulus recruits all available motor units
d) Subthreshold stimulus decreases motor unit recruitment, threshold stimulus recruits all available motor units, maximal stimulus increases motor unit recruitment