C. Mammary gland. Hope this helps!
Maybe if you insert a picture, we can help you.
Two species of sea urchins live practically side-by-side in sandy bottoms. The two species appear to have the same diet: drift seaweeds and other bits of organic matter. They can live in the same environment without competing.
As it compels them to live in the same environmental surroundings so the characteristics of living nature also get developed as their current following situation that's helping them to get the same food & habitat.
<span>the foramen magnum </span>most likely<span> be located in </span>back of the skull