C) Since the allowable increase is 333,33 units - the extra 100 units will be 100 times the first unit (the objective function will increase linearly as the capacity increase on engine assembly - till 4333.33). You can re run the model with new numbers plugged in.
(Please show this).
Please see the solution -- I have solved what you asked for above [ re running ...
The solution assists with answering the optimization problem.