Lutetium-177 is an ideal therapeutic radioisotope because it is a strong B emitter and emits just enough y radiation to enable imaging.
What is the stable daughter nuclide produced from the decay of this radioisotope?

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.