Find, which of the following sets are empty:
(i)The set of points of intersection of two parallel lines.
(ii) A={x:x∈N and 5< x≤6}
(iii) B={x:x2+4=0,x∈N}
(iv)C={even numbers between 6&10}
(v) D={prime numbers between 7&11}
Note : The set, which has no element in it, is called the empty or null set.