In the context of wearable technology, which of the following tasks is /are accomplished by wearable devices?
1. Location identification of a person.
2. Sleep monitoring of a person.
3. Assisting the hearing impaired person.
Select the correct answer using the code given below.
1) 1 only
2) 2 and 3 only
3) 3 only
4) 1, 2 and 3