Someone be my frien plz

Literary criticism, critic and critique

What is the term for a recurrent musical section between various contrasting sections? a. concerto grosso b. basso ostinato c. fugue d. ritornello

To create an illustration of perspective, this artist did all of the following except 1) show clear orthogonal lines 2) have an implied vanishing point 3) distort proportion to keep the background and foreground the same size 4) include value changes between the foreground and background i was thinking maybe 1