I would say D, because you need to start with nothing to measure the different sizes as they start to grow. hope this helps!
They are both made up of the same protein called "histones".
The answer is (4) Ag(s)
Solid Silver has a Face Centered Cubic crystal structure.
The remaining choices are gases (H2 & Ar) and liquid (Br). Liquids and gases do not form crystal structures as their atoms are loose.
