Final answer:
The displacement when running in the negative direction at 12m/s for 9 seconds is -108 m, which is option B).
Step-by-step explanation:
If you run in the negative direction at 12 m/s for 9 seconds, your displacement is calculated by multiplying your speed by the time. Therefore, the displacement is 12 m/s multiplied by 9 s, which equals 108 m. However, since you are running in the negative direction, your displacement is in the negative direction as well. Thus, the correct answer is -108 m, which corresponds to option B).