True about coronory sinus:: (A) Remnant of left horn of sinus venosus, (B) Great, middle & small cardiac vein drain into it, (C) Thebesian valve guard its opening, (D) All
Answer is D. A i.e. Remnant of left horn of sinus venosus; B i.e. Great, middle & small cardiac vein drain into it; C i.e. Thebesian valve guard its opening