The second cranial nerve of the frog is:

The $Y$-shaped bone is:

$A$ Bidder's canal in each kidney of frog:

In a frog,the eyelid is .....

Consider the following four statements $(A-D)$ related to the common frog $Rana$ $tigrina$,and select the correct option stating which ones are true $(T)$ and which ones are false $(F)$.
Statements:
$A.$ On dry land it would die due to lack of $O_2$ if its mouth is forcibly kept closed for a few days.
$B.$ It has a four-chambered heart.
$C.$ On dry land it turns uricotelic from ureotelic.
$D.$ Its life-history is carried out in pond water.

Describe the structure of the kidney in a frog.