From figure, the correct relation is

In ⁡ΔMNO,A→+C→−D→=0⇒C→−D→=−A→Hence, (2) is correct. In ΔMNP,A→+B→+E→=0Hence, (1) is correct.In ⁡ΔMPNO,−E→−B→+C→−D→=0⇒B→+E→−C→=−D→Hence, (3) is correct.