Marcy purchases a total of 12 adult, child, and senior tickets for an art museum tour. Adult tickets are $5 each, child tickets are $2 each, and senior tickets are $4 each. If she purchases 4 more child tickets than senior tickets and spends a total of $38, which statement is true? A. The solution to this system is nonviable because it results in negative values of tickets. B. The solution to this system is viable. C. The solution to this system is nonviable because it results in fractional values of money. D. The solution to this system is nonviable because it results in fractional values of tickets.