Answer:
B, C
Step-by-step explanation:
You want to know which of the listed objects appear to be moving relative to your seat on the bus you are riding.
Relative motion
Anything that is not rigidly in place on the moving bus will appear to be in motion relative to the bus. We presume the seats and floor are attached to the bus, so from your perspective they are stationary.
The moving objects will include ...
B. the street outside
C. the clouds above