Short answers, pulled from the story.
Austrian foreign minister Klemens von Metternich designed the peace proposal in November 1813. He took charge of drafting the terms under his close supervision and convened meetings with other Allies in Frankfurt to finalize the text.
The Pyrenees marked the southwest border with Spain, the Alps defined the southeast border with Italy, and the Rhine River served as the eastern boundary with German States. France would keep control of Belgium, Savoy, and the Rhineland region while surrendering occupied territories elsewhere.
Baron de Saint-Aignon delivered the final version of the proposal to Napoleon in November 1813. This delivery occurred after a private meeting between Napoleon and Metternich in Dresden in June 1813.
London rejected the terms because they might allow Belgium to become an invasion base for Britain. The fear centered on Belgian territory serving as a launch point for attacks against British interests.
Napoleon was forced to abdicate on the 6th of April 1814. This event marked the end of his rule over France after Paris surrendered to Allied forces.