Evaluate. (Be sure to check by differentiating!) ( 415 - 8) 1 at . . . Determine a change of variables from t to u. Choose the correct answer below. O A. U= 14 O B. u=14 - 8 O C. u= 4t - 8 O D. U= 4t - 8 Write the integral in terms of u. J ( 415 - 8 ) 1 at = JD du (Type an exact answer. Use parentheses to clearly denote the argument of each function.) Evaluate the integral. J ( 415 - 8) 14 at = ] (Type an exact answer. Use parentheses to clearly denote the argument of each function.)