Which of the following bears actin binding site?

Meromyosin bears actin binding site. Myosin head had binding sites for both ATP and actin.

Titin is a giant structural sarcomeric protein with a molecular weight of more than 3800 kD. 

Troponin is a regulatory, trimeric protein of thin filament. It has binding sites for calcium ions and tropomyosin.

Tropomyosin is another regulatory protein of thin filament. In relaxed muscle, myosin is blocked from binding
to actin because strands of tropomyosin cover the myosin- binding sites on actin.