Study the following statements regarding contractile proteins of muscle. Identify the correct statements:
I. Actin is a protein present in thin filament present in I-band of a sarcomere.
II. Myosin forms the thick filament and contains ATPase activity in its tail region.
III. Troponin binds calcium ions and helps in exposing the active sites on thin filament.
IV. Tropomyosin actively hydrolyses ATP during muscle contraction.