Solve the equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. 6 x plus 21 equals 3 Question content area bottom Part 1 Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The solution set is StartSet nothing EndSet . (Type an integer or a simplified fraction.) B. The solution set is {all real numbers}, so the equation is an identity. C. The solution set is empty set, so the equation is a contradiction