A. m = 0 || This is incorrect, because m being equal to 0 is a solution in and of itself.
B. m = m || This is incorrect, because m being equal to itself means that there are an infinite number of solutions.
C. 2m + 1 = m - 2 | m = -3 || This is incorrect, because m can be solved for and has a solution.
D. m + 4 = m - 4 | 4 = -4 || This is correct because 4 is not equal to -4, and thus there is no solution.
Hope this helps!! :)
