The cooling effect in refrigeration is obtained by:

(i) Mechanical refrigeration technique

(ii) Passing a direct current through the junction of two dissimilar metals

(iii) Sublimation of carbon dioxide

(iv) Throttling of a real gas Which of the above statements are correct?

(a) (i) and (ii)

(b) (i), (ii) and (iii)

(c) (i), (ii) and (iv)

(d) (i), (ii), (iii) and (iv)