7. Jay-R analyzes an unknown liquid. He takes samples from the top, middle, and
bottom of the samples. Which observation would allow him to reach the
conclusion that the liquid could be a pure substance?
a. All three samples have different boiling points
b. All three samples have the same boiling point.
c. The top and middle samples have the same boiling point, which differs
from the boiling point of the bottom sample,
d. The middle and bottom samples have the same boiling point, which
differs from the boiling point of the top sample

i need the answer rn pls!!,​