Complex sentence: Finally, the European Commission, the executive body of the EU, is accountable to Parliament: in particular Parliament elects the President of the Commission, and approves (or not) the appointment of the Commission as a whole.
Split into simpler sentences: Finally, the European Commission, the executive body of the EU, is accountable to Parliament. In particular, Parliament elects the President of the Commission, and approves (or rejects) the appointment of the Commission as a whole.