What does it mean when two objects are said to exert a mutual force of attraction? A. Each takes turns attracting the other. B. They attract each other at the same time.
C. A third object takes turns attracting each of them.
D. A third object attracts them both at the same time.

B

It says "mutual", so both objects are attracting at the same time. In addition, I do not believe it is possible for objects to take turn acttracting each other so I believe A is false. I think C and D are wrong because a third object is not related to any of these choices. It also explicitly states "two objects" and when it says mutual, it means they are attracting each other.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation