The correct answer is (c) 0
To explain I would say: The unit sample response of the Hilbert transformer is given as
h(n)=\(\frac{2}{\pi} \frac{(sin(\frac{πn}{2}))^{2}}{n}\); n≠0
h(n)=0; n=0
From the above equation, it is clear that h(n) becomes zero for even values of ‘n’.