Which of the following is correct way of copying the values of pair p1 into other pair p2?

• A. pair <type,type> p2 = p1;
• B. pair <type,type> p2(p1);
• C. Both pair <type,type> p2 = p1; and pair <type,type> p2(p1);
• D. Pair <int,int> p2.copy(p1);