Lack of artifacts from the prehistoric period can be overcome in the study of art history by virtue of
a. assertions made by ancient historians
b. common features shared by all works of art
c. comparisons with other prehistoric works
d. reliance upon available written records

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 !

the answer is false i think