The first thing you decide to do is to build a fire. However, you have no matches, so you use the bow-and-drill method. What is the bow-and-drill method?

a. A dry, soft stick is rubbed between one’s hands against a board of supple green wood.

b. A soft green stick is rubbed between one’s hands against a hardwood board.

c. A straight stick of wood is quickly rubbed back-and-forth against a dead tree.

d. Two sticks (one being the bow, the other the drill) are struck to create a spark.