Multi-choice problem: Continue writing the next sentence in this paragraph:

They cut up an avocado and put it on a sandwich. They put mayonnaise on top of the sandwich. they

Available options:
i. add grated mayo on top which they layer with dressing..
ii. cut on the cutting board and the sandwich is done..
iii. cut a piece of bread on a cutting board..
iv. put a piece of bread on top of the sandwich..
iv.