A company just starting business made the following four inventory purchases in June:

Date Units Amounts

June $1150$ units $2,600$

June $10200$ units $3,900$

June $15200$ units $4,200$

June $28150$ units $3,300$

$14,000$

A physical count of merchandise inventory on June $30$ reveals that there are $100$ units on hand. The inventory method which results in the highest gross profit for June is

one:

a$.$ not determinable.

b$.$ the specific identification method.

c$.$ the FIFO method.

d$.$ the average$-$cost method.