That would be D. Isovolumic contraction
As the name states during ISOvolumic contraction the volume of the ventricles doesn’t change and stays the same so no blood enters or leaves the ventricles. The thing that changes is the pressure of the ventricles that increases.
I can explain the process more if u want in the comments:)
It would be a blob of muscle and veins
D is the answer! I just had this question and it was right !
I believe it is class, because species are divided into different classes, but families, for example: there's the cat family, and there's the dog family. classes: the carnivores, herbivores, omnivores OR mammals, egg laying, or hermaphrodites