As shown in the image above, the earth's outermost layer is divided into several tectonic plates. which of the following is true about these plates?
a.
the plates move either toward or alongside each other, but not away from each other.
b.
some plates move toward each other, while others move away from or alongside each other.
c.
all of earth's tectonic plates move toward each other.
d.
all of earth's tectonic plates move away from each other.

u i forgot the answer?

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.