A String,30 Cm Long and Having a Mass of 45

A string,30 cm long and having a mass of 45 g,is attached to a 810 Hz vibrator at one end.The other end of the string is fixed and the string is kept under tension.The vibrator produces a transverse wave in the string,whose amplitude is 7.0 mm,and that propagates with a velocity of 76 m/s.The energy of the wave is absorbed at the fixed end.In this situation,the tension in the string,in SI units,is closest to:

A) 870
B) 830
C) 900
D) 940
E) 970