Which of the following could be considered the most recent common ancestor of living tetrapods? a) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates b) an armored, jawed placoderm with two pairs of appendages c) an early ray-finned fish that developed bony skeletal supports in its paired fins d) a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes

a) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates.

Explanation:

An ancestor - An earlier type of a species at any distant time — a progenitor.

A tetrapod is any vertebrate with four limbs. It includes any vertebrate (such as birds or snakes) that have evolved from early tetrapods — especially all members of the superclass Tetrapoda.

The presence of bones that support the appendages in Lobe – fin fish were found to be similar to the categorical skeletal supports found in the limbs of sample tetrapods. The sub class crossopterygii includes the Lobe – fin fish, which is seen as one of the recent common ancestor of living tetrapod today.

the "dirty dozen" chemicals banned in an international treaty are formally known as persistent organic pollutants, or pops. the united nations environment program provided this background on what they are and what they can do to humans and wildlife.

i hope this

helicase, i think thats it