If \(a, b, c,\) and \(d\) denote positive integers in the figure above, what is the value of the product \(abcd?\)

(1) In each of the columns \(S\) and \(T,\) the product of the three numbers equals the product of the four numbers in row \(R.\)
(2) \(a + b + c + d = 26.\)

Answer: A

Source: GMAT Prep