When Measuring GDP,economists Count Only the Values of Final Goods

When measuring GDP,economists count only the values of final goods and services because

A) the final value is taxable
B) adding the values of intermediate products is too difficult a task
C) the value of all intermediate products is automatically included in the value of those final goods
D) intermediate products are overpriced
E) the final cost is the selling price,which is what economists want to know