The European Council primarily serves as a strategic body that sets the overall political agenda and priorities of the European Union, but it does not directly pass laws or adopt budgets. Therefore, from the options provided, none precisely describe its main functions. However, for clarity:
A. Passes laws and adopts budgets - This is primarily the role of the European Parliament and the Council of the European Union, not the European Council.
B. Resolves disputes among members - This is more within the purview of other institutions, like the Court of Justice of the European Union, rather than the European Council itself.
C. Insures legislation is applied fairly - This is generally the role of the European Commission and the Court of Justice.
D. Represents the EU globally - The European Council does represent the EU at the highest political level in international relations and discusses external issues, so this would be the closest option.
Thus, the best answer among the choices given would be D: represents the EU globally.