End item A requires three component parts: B$,$ C$,$ and D$.$ The bill of materials indicates that for each completed A$,2$ units of B$,2$ units of $C,$ and $1$ unit of $D$ are required. Current inventory for the four items is as follows: there are $18As,40Bs,50Cs,$ and $35Ds$ in stock. If the lead time for all items is one week and there are no scheduled receipts for any item, how many units of product A can be delivered to customers at the start of next week $($week $2)?$

$43$

$38$

$31$

$15$