Answer: A. The alleles that a person has.
The signs and symptoms of a cluster headache include severe<span> right-sided headache with a runny nose, droopy eyelids, and tearing of the eye on the right side.
</span>The injectable form of sumatriptan<span> (</span>Imitrex<span>), which is commonly used to treat a migraine, is also an effective treatment for acute cluster headache</span>
Mutation causes change in an organisms DNA, resulting in a change in all aspects of the organisms life. It affects how the organism looks, and how it behaves. If there was no mutation, an organism could not change, therefore there wouldn't be evolution at all.
They share common ancestry