Express the signal shown in the diagram below in terms of unit step functions.
1
x(t) = u(t - 1) + 2u(t) -u(t + 1) -u(t + 2) -u(t + 3)
2
x(t) = u(t + 1) + 2u(t) -u(t - 1) -u(t - 2) -u(t - 3)
3
x(t) = -u(t - 1) - 2u(t) + u(t + 1) + u(t + 2) + u(t + 3)
4
x(t) = -u(t + 1) - 2u(t) + u(t - 1) + u(t - 2) + u(t - 3)