Solve. 1 8 2 \"*3 X+5=x2+ax+15 Select the correct choice below and, if necessary, ll in the answer box to complete your choice. D A- The solution set is D. (Type an exact answer, using radicals and i as needed. Use a comma to separate answers as needed.) C) B. The solution set is the set of all real numbers. C) C. The solution set is an empty set