Correct answer is (c) four
Best explanation: A transistor has four h-parameters –
H11 = V1/i1 (Input Impedance with output short circuited)
H21 = i2/i1 (Current gain with output short circuited)
H12 = V1/V2 (Voltage gain with feedback ratio with input terminals open)
H22 = i2/V2 (Output Admittance with input terminals open).