What does Ariel give to the sea witch Ursula in exchange for her humanity?

Explanation

Ariel the mermaid falls in love with Prince Eric, a human, but her father, King Triton, does not like humans. Consequently, the little mermaid recruits the aid of the sea witch Ursula, who makes her human for three days in exchange for her voice. To get her voice back, Arial must receive a kiss of true love from the prince within three days. The Little Mermaid was adapted for the screen by Disney in 1989 based on the fairy tale of that name by H. C. Andersen. Walt Disney had actually attempted to retell the story of the little mermaid himself in 1940.