Let T be a shear transformation that leaves e₁ unchanged and maps e₂ into e₂ - 3e₁. If the standard matrix of T is [[a, b], [c, d]], find a, b, c, and d.

a) 1, 0, -3, 1
b) 1, -3, 0, 1
c) 0, 1, -3, 1
d) -3, 1, 0, 1