The forelimb structure seen in both bat wings and human arms is very similar to that of an extinct land animal called eusthenopteron. this fact suggests that
bats evolved from humans
eusthenopteron might be a common ancestor of bats and humans
in the future, bat wings might evolve hand-like limbs
science is full of coincidences

The correct answer would be Eusthenopteron might be a common ancestor of bats and humans.

It can be explained with the help of homology. Homology refers to the similarity found in structure, physiology, development or genes of organisms of different species.

For example, homologous organs which refers to the organs which have similar anatomical structure but plays different functions.

Homology suggests that the organisms which have homologous organs (or other homology) are considered to be evolved from a common ancestors. These organs are adapted to serve different functions in different organisms.

Thus, due to homology present in the forelimb structure of the bat wings, human arms, and Eusthenopteron, we can conclude that human and bats might have evolved from the common ancestor Eusthenopteron.

what have fossils ever done for you

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme