How do incised meanders develop with no floodplains and deep canyons, like those found in the Colorado Plateau?
a. Youthful streams recently began to cut down due to raising of sea level.
b. As sea level dropped, the original youthful streams matured into old streams.
c. As sea level rose, the original, old streams were rejuvenated.
d. A new stream began to flow in an old canyon.
e. Original, mature meandering streams began to downcut rapidly due to a rapid and continual lowering of base level (rising of the land).