COULD YOU TELL ME WHAT A...IS USED FOR

1/ - HE THONG DE KIEM TRA TRAC NGHIEM 15''''ANH 10 CB 2
HE THONG DE KIEM TRA TRAC NGHIEM 15''''ANH 10 CB 2

1/ Could you tell me what a...is used for? -Well , it is used to send and receive letters quickly.

a

cell phone

b

fax machine

c

air conditioner

d

printer