Which one of the following has a poison gland?

External ears or pinnae are characteristic features of which group of animals?

In which of the following groups does the aortic arch curve to the left?

The long neck of a camel is due to:

Note the following:
$I.$ Dentition is heterodont.
$II.$ Canines are poorly developed.
$III.$ Incisors are chisel-like,poorly developed.
$IV.$ Herbivorous and diastema is present.
$V.$ The dental formula is $I \frac{2}{1}, C \frac{0}{0}, P m \frac{3}{2}, M \frac{3}{3}$.
Which of the above are true for $Oryctolagus$?

$A$ : Bats and whales are classified as mammals.
$R$ : Bats and whales show echolocation and four-chambered heart.