The decimal number system uses the characters $0,1,2, \ldots, 8,9$, and the octal number system uses the characters $0,1,2, \ldots, 6,7$.
For example, the decimal number $12\left(=1 \times 10^{1}+2 \times 10^{0}\right)$ is expressed as $14\left(=1 \times 8^{1}+4 \times 8^{0}\right)$ in the octal number system.
The decimal number $108$ in the octal number system is
- $168$
- $108$
- $150$
- $154$