I took the test and the answer is 6 units²
As a bonus:
this is what the rectangle would look like:
shown work:
width = sqrt [(-4 - -3)^2 + (0 – 1)^2] = sqrt (2)
length = sqrt [(-3 - 0)^2 + (1 – -2)^2] = sqrt (18)
Area = length * width
Area = sqrt (2) * sqrt (18)
Area = 6
Hope this was helpful!