In regression analysis, if observed cost value is 50 and predicted cost value is 7, then disturbance term will be

The correct answer is $\boxed{\text{B) }43}$.

The disturbance term is the difference between the observed value and the predicted value. In this case, the observed value is 50 and the predicted value is 7, so the disturbance term is 50 – 7 = $\boxed{\text{43}}$.

Option A is incorrect because it is the sum of the observed value and the predicted value, not the difference. Option C is incorrect because it is the predicted value, not the difference. Option D is incorrect because it is the observed value, not the difference.