The correct option is C Tetanus
A tetanic contraction is a sustained muscle contraction evoked when the motor nerve that innervates a skeletal muscle emits action potentials at a very high rate.
Spasm is sudden involuntary muscular contractions but the contractions do not sustain for a long period.
Muscle fatigue is the decline in the ability of a muscle to generate force.
Tonus is the constant low-level activity of a muscle, even in the passive state, to maintain the posture of the body