Right answer is (c) Z
Explanation: Y-parameter = \(\frac{1}{Z}\)[1; -1; -1; 1]
And from the definition of the Y parameters, ∆Y = 0. Therefore the Y-parameter exists.
Since ∆Y = 0, so by property of reciprocity, ∆h = 0 and ∆g = 0.
Hence both hybrid and inverse hybrid parameters exist.
But the Z-parameters cannot exist here because if one terminal is opened the circuit will become invalid.
∴ Z- parameters do not exists.