Use the Following Tables to Answer the Next Questions $\begin{array}{|l|l|l|l|}\hline \text { CustCode } & \text { InvNo } & \text { EmpCode } & \text { InvDate } \\\hline\end{array}$

Use the following tables to answer the next questions. Neither the order in which the data elements are presented in these tables nor the capitalization of the names of the data elements has any significance.Invoice TableInvoice Line TableInventory TableEmployee TableCustomer Table
Invoice Table
$\begin{array}{|l|l|l|l|}\hline \text { CustCode } & \text { InvNo } & \text { EmpCode } & \text { InvDate } \\\hline\end{array}$
Invoice Line Table
$\begin{array}{|l|l|l|}\hline \text { Qty } & \text { InvNo } & \text { ProdNo } \\\hline\end{array}$
Inventory Table
$\begin{array}{|l|l|l|}\hline \text { ProdNo } & \text { Desc } & \text { Price } \\\hline\end{array}$
Employee Table
$\begin{array}{|l|l|l|}\hline \text { EmpName } & \text { EmpCode } & \text { CommRate } \\\hline\end{array}$
Customer Table
$\begin{array}{|l|l|l|}\hline \text { Name } & \text { City } & \text { CustCode } \\\hline\end{array}$
-Which of the following would be the primary keys of the first three tables above?

A) CustCode, InvNo, ProdNo
B) InvNo, InvNo/ProdNo, ProdNo
C) InvNo/CustCode, ProdNo/Qty, ProdNo
D) InvDate/InvNo, ProdNo, Desc