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

How to find air leaks in your home
Use the hand test to find air leaks.
On a cold day with the heat on inside your home, place your hand around the edges of all exterior doors, windows, and bathroom and kitchen air vents and fans. If you feel cold air on your hand, then you have an air leak.

Select from:
(1). To feel warm air on your hand, press your hand back against the wall or window when you are outside or in a garage. Keep in mind that door door panels could also be damaged by hot air inside and you may need to use a special air test kit for this..
(2). There is no need to use the hand test if you believe that there is a leak. The words are intuitive and your gut instincts need it..
(3). You can also use the hand test to detect leaks around electrical outlets. The hand test is best for finding large leaks of air coming into the home..
(4). You can also find air leak detector devices online or at your local law enforcement office. Those devices wear polarized lens shields and can magnify visible size leaks..
The answer is:
(3).