A student measures the thickness of a wire using a screw gauge with a pitch of $1\text{ mm}$ and $100$ divisions on the circular scale. If the zero error is $+0.03\text{ mm}$ and the observed reading is $2.45\text{ mm}$, what is the corrected thickness?

1. A.$2.42\text{ mm}$
2. B.$2.48\text{ mm}$
3. C.$2.45\text{ mm}$
4. D.$2.43\text{ mm}$