what is the domain of the letter g?

Answer:
B
Step-by-step explanation:
recall that any radical expression [tex]\sqrt{A}[/tex] has real solutions only if A is not negative. (otherwise you will have imaginary solutions)
hence in this case we have
[tex]\sqrt{8x}[/tex],
for real solutions, 8x must be ≥ 0,
since 8 is a positive number, x must be ≥ 0 (answer)