By how much is a signal’s strength reduced when the signal passes through an object thatintroduces 3 dB of attenuation？（）

A.less than 10 percent
B.10 to 15 percent
C.15 to 20 percent
D.25 to 30 percent

A.Class A
B.Class 1
C.Class 2
D.Class 3
E.Class 4

A.5 to 10 percent for both 2.4 GHz and 5 GHz
B.10 percent for both 2.4 GHz and 5 GHz
C.20 percent for 2.4 GHz and 15 to 20 percent for 5 GHz
D.20 percent for 2.5 GHz and 10 percent for 5 GHz