The correct answer is A. 15.67 per piece.
The budgeted indirect cost rate is calculated by dividing the budgeted annual indirect cost by the budgeted annual quantity of cost allocation base. In this case, the budgeted annual indirect cost is $60000 and the budgeted annual quantity of cost allocation base is $3600. Therefore, the budgeted indirect cost rate is $60000 / $3600 = 15.67 per piece.
Option B is incorrect because it is the budgeted annual indirect cost per piece, not the budgeted indirect cost rate.
Option C is incorrect because it is the budgeted annual quantity of cost allocation base per piece, not the budgeted indirect cost rate.
Option D is incorrect because it is less than the budgeted indirect cost rate.