There are MANY subatomic particles in an atom.
But the three most important ones are
The electron which has a negative charge.
The proton having a positive charge.
And the neutron which is neutral or which has no charge at all.
The protons and neutrons club together and form the inner, heavy part of the atom which is positively charges because of the protons known as the nucleus.
And electrons remain farther away in all reality and revolve around the inner positive nucleus.
Trying its best to make the whole atom neutral!
The answer is going to be C) because
A)We know that she put all three boxes in the window and let them sat their for a hour
B)We know that the boxes are the same size
C)She used three different materials,and she wants to measure the warmth of each box. To see which one is the warmest
D)She never said anything about mass
Hopes This Helps:)