Multi-choice problem: Choose from the options at the end, and answer how do you do this: How do you prepare boiled yams to be cooked?

Available options: (I). Clean, peel, and trim the yams. Then, cut the yams into cubes that are about inch to 1 inch in size. Each cube should be approximately the same size.; (II). Clean, peel, and trim the yams. Then, cut the yams into cubes that are about inch to 1 inch in size. Each cube should vary in size.;
(I).