Which of the following are examples of empty set? (i) Set of all even natural numbers divisible by 5. (ii) Set of all even prime numbers. (iii) {x: x^2 – 2 = 0 and x is rational }. (iv) {x: x is a natural number, x less than 8 and simultaneously x greater than 12}. (v) {x: x is a point common to any two parallel lines }.