The blood pumped by the $A$ ventricle enters the $B$ artery,whereas the $C$ ventricle pumps blood into the $D$. Choose the correct option for $A, B, C$ and $D$.

The post-caval vein collects blood from

Papillary muscles are found in mammalian

$SA$ node (Sinoatrial node) ke baare mein sahi kathan chuniye:
$I$. Located at the right upper corner of the right atrium.
$II$. Heart of heart.
$III$. It initiates the rhythmic contractile activity of the heart.
$IV$. It is called the pace-keeper of the heart.
$V$. It is called the pacemaker of the heart.
Which of the following options contains the correct statements?

Systemic heart refers to

The tricuspid valve is located between.......