Examine one argument for the existence of God.

There are three main arguments for God’s existence: the Ontological Argument, the Teleological Argument and the Cosmological Argument. Each argument has been examined in different ways by different philosophers.This question is looking for one explanation of one argument. It’s an ‘examine’ question - therefore it wants the pros and cons with a conclusion: a cross-referenced comparsion of them and a conclusion about which is more effective. Stronger candidates will be able to identify criticisms from specific philosophers of both arguments.
For example: ‘Anselm in his ontological argument explains that God is “something than which nothing greater can be conceived”.’ This would be explained with the criticisms for it outlined, or with a comparsion to a contrasting version of the ontological argument. For example, a student could mention Hume’s ‘a priori’ critcism, or Gaunilo’s criticism of Anselm and conclude which argument is most effective.