Which reaction releases the greatest amount of energy per kilogram of reactants?
a) neutron + uranium-235 ➡️ barium-141 + krypton-92 + 3 neutrons
b) 2c + h2 ➡️ c2h2
c) c3h8(g) + 5o2(g) ➡️ 3co2(g) + 4h2o(l)
d) naoh(aq) + hcl(aq) ➡️ nacl(aq) + h2o(l)

can you also explain why it's the right answer or why the other choices are wrong?

The answer is A. It shows a nuclear type of reaction, specifically nuclear fission reaction. Nuclear fission is the splitting of heavy nucleus into lighter nuclei. Large energies from nuclear reactions are due to the process of splitting the atoms apart. The bonds that keep together the parts of an atom has much higher energies than the chemical bonds in a molecule about a million times. Thus, when you try splitting the parts of an atom these energies are released which may cause an explosion when not properly handled.

10.063g / 10.00 ml = 1.0063 g/ml which rounds off to 4 sig figs as: 1.006 g/ml

The net force is 100