C. Because protons are the identity of the atom.
The cheetah's speed is 100x and
The gazelle's speed is 80x + 70.
Set the two equations equal to each other:
100x = 80x +70 (then subtract 80x from both sides).
20x = 70 (then divide by 20).
X =3.5.
The cheetah catches the gazelle after 3.5
<em>Steel: 11.0 – 12.5</em>
<em>T̶e̶t̶s̶u̶t̶e̶t̶s̶u̶ ̶T̶e̶t̶s̶u̶t̶e̶t̶s̶u̶</em>
Thanks,
<em>Deku ❤</em>