the cartesian equations of a line are (x-1)/2 = (y+2)/3 = (z-5)/-1 is vector equation is
a. r = (-i+2j-5k) + λ(2i+3j-k)
b. r = (2i+3j-k) + λ(i-2j+5k)
c. r = (i-2j+5k) + λ(2i+3j-k)
d. none of these