Answer: A Radium
Explanation:
Thorium-232 is an alpha-emitting radionuclide, which decays to radium-228, which is a beta emitter with a half-life of about six years.
<span>The plates make up Earth's outer shell, called the lithosphere. (This includes the crust and uppermost part of the mantle.) Churning currents in the molten rocks below propel them along like a jumble of conveyor belts in disrepair. Most geologic activity stems from the interplay where the plates meet or divide.</span>
I don't see an image, but the force of gravity depends on mass and distance. If the mass and the distance are different, you divide (mass÷distance).the greater the number the greater the force of gravity.
Tell me if you need more info.
The answer more than likely based on research would be (B.)
