He is . A. Element
B. Composite
C. Homogeneous mixtures
D. Heterogeneous mixtures

A. Element

Explanation:

He is a symbol of an element called helium. Helium is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas (gas whose atoms are not bound to each other). It's the first in the noble gas group in the periodic table. As we can see in the attached image, its atomic number is 2.

Helium is known for causing people to have a high-pitched voice after being inhaled. Because it is lighter than air, when you inhale it and try to talk, the sound waves travel faster through the lower-density gas, resulting in a high-pitched voice.

answer; i believe that the correct answer is ; males are hemizygous for the x chromosome;