Given the question: Given the following context:  In 1971, Camilla Shand meets Charles, Prince of Wales at a polo match. They get to know each other and begin dating. The relationship fizzles out when Charles travels overseas to join the Royal Navy in early 1973. Camilla immediately marries her ex-boyfriend Andrew Parker Bowles. Though Charles is hurt upon hearing about her marriage, they remain friends. Throughout their friendship Charles and Camilla hide their feelings for each other until 1979 when Lord Mountbatten is murdered and Charles visits her more for emotional support. They re-ignite their romantic relationship during this period. Charles is now in his early 30s and his family and the British media begins calling him out to find a suitable bride. He meets Lady Diana Spencer who the media falls in love with and they eventually get engaged. Although everyone is happy Charles is about to settle down, Charles and Camilla are not due to their feelings for each other, however, they end their relationship. The story ends with Charles and Camilla getting ready for his wedding in 1981, both looking grim while dressing up for the occasion.  answer the following question:  What is the title of the person that gets engaged to Lady Diana Spencer?
The answer is:
Prince of Wales