Fossil contents of the alimentary canal are termed as

$A$: Muscles of external ears are fully developed in humans.
$R$: These muscles help in moving the ear pinna in humans.

Which of the given pairs are correct?
$I.$ Wings of insects and birds are homologous organs.
$II.$ Wings of bats and birds are homologous organs.
$III.$ Wings of insects and bats are analogous organs.
$IV.$ Wings of insects and birds are analogous organs.
Choose the correct option.

The presence of gills in the tadpole of a frog indicates that:

Which of the following is $NOT$ a living fossil?

Which of the following is the most acceptable method for determining the age of recent fossils?