Answer:
a) & b) are true. c) & d) are false.
Explanation:
WTO is an international (intergovernmental) organisation, supervising international trade between countries.
a) is true. It seeks to establish impartial procedures for resolving trade disputes among its members.
It seeks to reduce remaining trade barriers through multilateral negotiations, b) is true
c) is false. It is headquartered in Geneva, Switzerland (not Belgium)
d) is false. Existence of the WTO has allowed most member countries to replace their local currencies with a universal currency beginning in 2002. It is an international trade organisation, not monetary policy organisation.