The correct option is
D Sex call for female
In frogs, males frogs can be distinguished by the presence of to attract a mate, the male frog croaks from a shallow puddle, sending out ripples that invite not just female frogs, but also hungry bats. Male túngara frogs croak from shallow puddles to attract mates. Male frogs grow pads on their forelegs that help them to grasp the females in an embrace known as amplexus.
So the correct answer is 'Sex call for female'.