The European Council primarily serves to provide political direction and oversight for the European Union. However, in the context of your question regarding what the European Council does in terms of the governance of the EU, the best answer is:
D: Represents the EU globally.
While other institutions, like the European Parliament and the Council of the EU, are more directly involved in passing laws, budgets, and resolving disputes among member states, the European Council plays a key role in shaping the EU’s overall political agenda and representing the EU on the global stage.