How did the raccoon population become such a big problem in Japan?
People have continued to breed them.
They have no natural predators.
The Japanese do not believe in killing them.
The bears that used to eat them are extinct.

the correct answer would be d. hope this !

catya your not at all which answer i've seen you do this on another question!

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.