For a discrete time filter to be causal and to have exact linear phase
(A) Its impulse response must be of infinite length
(B) Its impulse response can be of any length
(C) The signal should be left sided
(D) Its impulse response must be of finite length
(A) Its impulse response must be of infinite length
(B) Its impulse response can be of any length
(C) The signal should be left sided
(D) Its impulse response must be of finite length