A. 0.1
The residual is the difference between the observed value and the predicted value for a data point. You obtain it by subtracting the predicted value from the observed value. So the predicted value is:
y = -0.2x + 1.9
y = -0.2*5 + 1.9
y = -1 + 1.9
y = 0.9
Therefore the residual is:
r = 1 - 0.9
r = 0.1
And the value of 0.1 matches option "A".
