Explain why new mexico and wyoming are part of the colorado river pact even though the colorado river does not run through these states?

New Mexico and Wyoming may contain rivers that eventually join the Colorado River. Even though the main stem of the Colorado River does not pass through these states, The rivers in these states may act as tributary rivers to the Colorado River. To understand this, you need to understand how water moves across the surface of the Earth from a higher elevation to a lower elevation, and the concept of a river catchment.   

Ithink that b is correct but just in case wait to see if someone else answers