The two major branches of mammals—the placentals and the marsupials—followed independent evolutionary pathways after the breakup of the land mass Gondwanaland 100 million years ago. While some forms of each group are unique to each environment, surprisingly similar forms in each of the groups have often emerged in two or three of the separated continents. This is an example of .
A) homologyB) parallel evolutionC) convergenceD) polyploidyE) gene duplication

Explanation:

Parallel evolution is a type of evolution in which two species evolve from a common ancestor sharing common characters and function is called parallel evolution

The species which evolve through parallel evolution are called sibling species

In the given example of mammals, placentals and marsupials both are mammals and share a common ancestor and function which followed independent pathways after the break up of Gondwanaland, so this reflects parallel evolution

after a the power stroke, adp is released, but the cross-bridge formed is still in place. atp then binds to myosin, moving the myosin to its high-energy state, releasing the myosin head from the actin active site.

if you listed your answers right then i believe your answer is b.