smc

There are only two possible occupants for the driver's seat. After the driver is chosen, any of the remaining three people can sit in the front, and there are two arrangements for the other two people in the back. Thus, there are $2\cdot 3\cdot 2=\boxed{12}$ possible seating arrangements. ~ aopsav (Credit to AoPS Alcumus) Alternative solution: If there was no restriction, there would be 4!=24 ways to sit. However, only 2/4 of the people can sit in the driver's seat, so our answer is $\frac{2}{4}\cdot 24=12\Rightarrow \text{(B)}$