The right answer is B.
Hydrogen is the most abundant element representing nearly three quarters of the mass of the universe.
Hydrogen is found in the water that covers 70% of the surface of our planet as well as in all organic matter.
Hydrogen is the simplest element in the universe. It is composed only of one proton (p) and only one electron (e-).
Hydrogen is the lightest element of all elements and gases; it is 14 times lighter than air. A "spill" of hydrogen gas immediately diffuses into the air and pollutes neither the ground nor the water table.
*Hydrogen is invisible, odorless and nontoxic. It does not cause acid rain, does not deplete the ozone layer and does not generate dangerous emissions.
