Which of the following statement/s is/are correct with respect to generation and conduction of nerve impulse?
i. The resting potential difference is -70mvs
ii. The voltage gated \(Na ^{+}\) and \(K^{+}\) channels operate together and are self closing.
iii. At the peak of action potential, the potential difference rises to +30 to +60mvs
iv. In medullated nerve fibre, the action potential is conducted wave as of membrane depolarization.
v. The resting potential is maintained by especially closure of gated channels of \(Na ^{+}\) and \(K^{+}\)

1. A i only
2. B iii and iv only
3. C ii, iv and v only
4. D i, iii and v only