Barb's shopping basket has items costing $7.90, $3.75, $4.15, and $4.20. what should Barb do to estimate her total cost.
A. multiply $4 by 4.
B. multiply $3 by 3 and add $8.
C. multiply $4by 3 and add $8.
D .Add the exact amounts and round up the total.
please help me