Shen's mother gave him $10 to go buy groceries . He picked up a gallon of milk for $3.49 , three pounds of oranges that cost $1.14 per pound , and a box of cereal for $3.46 . Shen used front-end estimation to determine whether he had enough money for the groceries . how much did he estimate the total cost would be A. he estimated that he had about $7 worth of groceries B. he estimated that he had about $9 worth of groceries C. he estimated that he had about $10.30 worth of groceries D. he estimated that he had about $10.40 worth of groceries