This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to roast yams
Preheat the oven to 175 degrees centigrade (350 degrees fahrenheit).
Line a baking pan or dish with aluminium foil.
Rinse the yams with water and rub off any dirt.

Select from the following. a). Wash them under cool, running water, and pat dry. Carefully place one ripe yams, buttocks first, in a mortar and pestle.; b). Cut the yam or yams. Depending on your preferences and the size of the yam, cut the yam into fourths, sixths, or eighths.; c). You may want to clean the yams inside and outside before roasting them. If you want to save time, you can omit the washing and cooking.; d). Scoop them off with a sieve. Rub the yams with a little salt and pepper to taste.;
The answer is:
b).