Is Used oil poured into a water drain in the street a non-point source solution or point source solution?

Non point source pollution

Explanation:

Point source pollution is when any contaminant enter the environment from an easily from an easily identified and confined place.

Non point source pollution is pollutants released in a wide space. Including oil, grease, and toxic chemicals.  

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.