请选择ABC4E1I*w5f)m6Z Mr. Carter is_______ English teacher.2C+C7R/J7G1G-H/@;f
A. a2C+C7R/J7G1G-H/@;f
B. these2C+C7R/J7G1G-H/@;f
C. an2C+C7R/J7G1G-H/@;f