The answer is C. There needs to be equal numbers of protons and electrons. If there are more or less electrons then the atom is no longer neutral!
The number of electrons will equal the number of protons In a neutral atom and the number of protons is the atomic number.
This is basics of organic chemistry - the element that has atoms that can bond with each other to form ring, chain, and network structures is (3) carbon.
The other elements available above cannot form such structures, whereas carbon, which is abundant in nature, can.
The acceleration is equal to force divided by mass which would be 100 / 50 which is 2 m/s2
