A $2$-bit flash Analog to Digital Converter $(ADC)$ is given below. The input is $0 \leq V_{IN} \leq 3$ Volts. The expression for the $LSB$ of the output $B_{0}$ as a Boolean function of $X_{2}, X_{1}$, and $X_{0}$ is
1. $X_{0}\bar{\left[X_{2} \bigoplus X_{1}\right]}$
2. $\bar{X_{0}}\bar{\left[X_{2} \bigoplus X_{1}\right]}$
3. $X_{0}\left[X_{2} \bigoplus X_{1}\right]$
4. $\bar{X_{0}}\left[X_{2} \bigoplus X_{1}\right]$