The direction ratios of the line which is perpendicular to the two lines x−7 / 2=y+17 / −3=z−6 / 1 and x+5 / 1= y+3 / 2= z−6 / −2 are
a. 4,5,7
b. 4,-5,-7
c. 4,-5,7
d. -4,5,8