Find a vector parameterization for the line that passes through P(2, 2, 1) and is parallel to the line r(t) = (i - j) tk.
a) r(t) = <2, 2, 1> + t <1, -1, 0>
b) r(t) = <2, 2, 1> + t <0, 1, 1>
c) r(t) = <2, 2, 1> + t <-1, -1, 0>
d) r(t) = <2, 2, 1> + t <1, 1, 0>