Question: How do you put insulation in a wall?

  Options: 
 A. Be sure the gaps between the board match the width of the insulation, use a pencil to cut the insulation to the correct vertical length, then press in by hand.
 B. Be sure the gaps between the board match the width of the insulation, use a blade to cut the insulation to the correct vertical length, then press in by hand.
Answer: B