Arman Company in Ningbo uses activity$-$based costing. The company produces two products: USB flashes $32$G and $64$G$.$ The annual production and sales volume of USB $32$G is $8,000$ units and of USB $64$G is $6,000$ units. There are three activity cost pools with the following expected activities and estimated total costs:ActivityCost PoolEstimatedCostExpected ActivityUSB $32$GExpected ActivityUSB $64$GTotalActivity $1$$$20,000100400500$Activity $2$$$37,0008002001,000$Activity $3$$$91,2008003,0003,800$ Using ABC, the cost per unit of USB $32$G is approximately:$1.$$ $6\mathrm{.}602.$$$6\mathrm{.}103.$$$7\mathrm{.}304.$$$5\mathrm{.}10$