A wire with original length $L_0$ is fixed at one end. A tensile force is then exerted on the other end, causing the wire to stretch to a new length $L_1$. What is the strain of the wire?
- A$\left(\frac{L_1}{L_0}\right) - 1$
- B$L_1 - L_0$
- C$\left(\frac{L_1}{L_0}\right) + 1$
- D$L_1 + L_0$