Electric Current Measures (In Amperes, or Amps) the Flow of Electrons

Electric current measures (in amperes, or amps) the flow of electrons through wires. Like traffic flow, the current entering an intersection of wires must equal the current leaving it. Here is an electrical circuit known as a Wheatstone bridge: $a = 5$ A, $b = 20$ A

If the currents in two of the wires are 20 amps and 5 amps as shown, determine the currents in the unlabeled wires in terms of suitable parameters.

A) $\begin{array} { l } x = 5 \\y = w - 20 \\z = 15 - w \\15 \leq w \leq 20\end{array}$

B) $\begin{array} { l } x = 15 \\y = w - 5 \\z = 20 - w \\5 \leq w \leq 20\end{array}$

C) $\begin{array} { l } x = 5 \\y = w + 5 \\z = 20 - w \\5 \leq w \leq 20\end{array}$

D) $\begin{array} { l } x = 20 \\y = w - 5 \\z = 20 - w \\5 \leq w \leq 20\end{array}$

E) $\begin{array} { l } x = 15 \\y = w + 5 \\z = 20 + w \\5 \leq w \leq 20\end{array}$