Read the following statements and choose the correct option:

Statement-I: Action potential generation in neuron follows all or no principle.

Statement-II: Higher than threshold stimulus causes larger amount of voltage change within in neuron.

Which of the following statements are correct?

(i) The cerebrum wraps around the thalamus.

(ii) Corpus callosum is characteristic of the mammalian brain.

(iii) Midbrain and hindbrain together form the brainstem.

(iv) Centres for hunger, thirst and temperature control are present in the hypothalamus.