The venous system of a frog differs from that of a mammal due to the presence of:

Ripe ova are shed by ovaries into

Match the description given in column $I$ with their examples given in column $II$ and choose the correct option.

Column $I$ (Description)	Column $II$ (Example)
$A$. Aquatic respiratory organ	$I$. Skin
$B$. Organ which acts as urogenital duct	$II$. Ureter and opens into the cloaca
$C$. $A$ small median chamber	$III$. Cloaca that is used to pass faecal matter,urine and sperms to the exterior
$D$. $A$ triangular structure	$IV$. Sinus venosus which joins the right atrium and receives blood through vena cava

In a frog,the pyloric sphincter is located between:

Statement-$I$: In frog,eyes and internal ears are well-organised structures.
Statement-$II$: Sensory papillae,taste buds,and nasal epithelium are cellular aggregations around nerve endings.

Frogs differ from humans in possessing$-$