Two wires are made of the same material and have the same volume. However wire 1 has cross-sectional area $A$ and wire-2 has cross-sectional area $3A$. If the length of wire 1 increases by $\Delta x$ on applying force $F$, how much force is needed to stretch wire 2 by the same amount?\\
(1) F\\
(2) 4 F\\
(3) 6 F\\
(4) 9 F