To be effective, key choices must me
a parallel
b broad
c specific
d diverse

The correct answer is A) parallel.

To be effective, key choices must be parallel.

A key is a device that allows biologist to identify an organism. These keys have contrasting statements required to make comparisons. We are referring to taxonomic keys that identify species or animals. When scientists try to identify an unknown organism they use taxonomic keys to do their research.

the function of the protein macromolecule is to move things in and out of the cell and transport other molecules in the body. there are many functions of proteins. they are the basic building blocks of living things and are responsible for the growth and repair of body cells and tissues.

explanation:

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.