Choose incorrect statement

Assertion : In a food chain, members of successive higher levels are fewer in number.
Reason : Number of organisms at any trophic level depends upon the availability of organisms which serve as food at the lower level.

Carnivores are

Consider the following statements about food chain

$I.$ The transfer of energy from producers to top consumers through a series of organisms is called food chain

$II.$ A food chain is always straight and proceeds in a progressive straight line

$III.$ In a food chain, there is unidirectional flow of energy from sun to producers and subsequently to series of different types of consumers

Which of the statements given above are correct?