What differs between a radioactive isotope and a stable isotope?

a. stable isotopes are shorter
b. radioactive isotopes last for less time
c. radioactive isotopes last longer.
d. there is no difference

 A radioactive isotope is emitting particles such as a fast moving electron or positron (radiation) and this is changing its structure. Eventually it may reach a stable configuration and will no longer decay. An stable isotope is simply a name for a form of an element which is chemically identical to other atoms of the element but with a different number of neutrons. I hope this helps!

That result from subduction of oceanic plates beneath lighter continental plates. most of the earth's volcanoes are located around the pacific ring of fire because that the location of most of the earth's subduction zones.