The correct answer is D. All of the above.
The WTO is run by its member governments. All major decisions are made by the membership as a whole. This is done through the General Council, which is composed of representatives from all member countries. The General Council meets at least once a month and is responsible for overseeing the day-to-day work of the WTO.
Some decisions are made by ministers who usually meet at least once every two years. These ministerial conferences are the highest decision-making bodies of the WTO. They are responsible for setting the overall direction of the organization and for negotiating new trade agreements.
Some decisions are made by their ambassadors or delegates who meet regularly in Geneva. These ambassadors and delegates are responsible for representing their countries at the WTO and for negotiating on their behalf. They also meet to discuss issues related to the implementation of WTO agreements and to prepare for ministerial conferences.
In conclusion, the WTO is run by its member governments. All major decisions are made by the membership as a whole, through the General Council, ministerial conferences, and their ambassadors or delegates.