The default values for Keccak f are
(a) c =1024 and r =576
(b) c =786 and r =832
(c) c =512 and r =1088
(d) c =512 and r =832
I got this question in an interview.
My doubt stems from Secure Hash Algorithms (SHA) in portion Other Public Key Cryptosystems and Cryptographic Hash Functions of Cryptograph & Network Security