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

How to make a crossbow out of a pen
Gather your materials.
You'll need a bic pen (they're usually white, and it must be a bic pen), a rubber band, scissors, toothpicks, and a small screwdriver.
Unscrew the top of the pen and put aside the ink-holder.

Options are:
a). Take out the crossbow and put it aside in your bookcase or kitchen drawer. Remove the sharpened top cap on the pen.
b). Cut off any off chunks from the top. Enjoy! Your crossbow! Get an a pen to sharpen your pen.
c). Rub down the bottom of the pen so it feels smooth. Trace three straight lines in dark colored graphite that connect your edges.
d). Cut the ends off of the pen. Cut the pen so it's 2-4 inches (5.1-10.2 cm) long.
The answer is:
d).