In a forest ecosystem,the pyramid of numbers is:

$A$: Ecological pyramids cannot explain all the vital functions of any ecosystem.
$R$: Pyramids actually do not explain the role of organisms working at more than one trophic level.

Which of the following statements is not correct?

Which of the following statements is true?

Which of the following statements is always true for an energy pyramid?

Give differences: Upright Pyramid and Inverted Pyramid.