El Castillo at Chichen Itza, Mexico, pictured here, is nearly solid, its walls interrupted by only a few small doors. What structural principle in architecture is this an example of?

a. Load-bearing construction

b. Hypostyle construction

c. Vaulting

d. The truss system

i'm not sure i completely understand your question, but i will do my best.

i think the answer you are looking for is sequence. (see below)

a repeated melodic fragment would be best defined as repetition, while repeated chords (different or the same) could be a chord progression. however, you then mentioned the chord and melodic fragment beginning on higher or lower pitches, in that case, the answer could be best defined as a sequence. the definition of a sequence is as follows: "the restatement of a motif or longer melodic (or harmonic) passage at a higher or lower pitch in the same voice."

let me know if this !