The following code will dim an LED. How many times will the body of this loop run? 22 brightness_step = 1/20; 23-for i=20:-1:1 24- write PWMDutyCycle (a, 'D9', i*brightness_step); disp (i); 25- 26- pause (.5); 27- end 20 times O 1 time O 1/20 times O 10 times