Task: Question Answering
Input (English): Passage: In 1783, Kitty is caught trying to pick the pocket of the painter Thomas Gainsborough. He offers to pay her more to sit for a portrait for him. There, she attracts the attention of Sir Hugh Marcy and the Earl of Carstairs. Sir Hugh, upon finding out her real social status, offers her a job as a scullery maid. Kitty learns that he is impoverished, having lost his post in the foreign office due to a scandal.
Gainsborough's portrait, The Anonymous Lady, creates a stir, as people try to guess who the subject is. The Duke of Malmunster buys both that painting and Gainsborough's The Blue Boy. When the duke asks Gainsborough who the model is, Sir Hugh claims she is his aunt's ward. The duke admits he may have been mistaken in having Sir Hugh dismissed from his position (in favor of the duke's nephew), and in exchange for an introduction to Kitty "Gordon", offers to reinstate him. Sir Hugh, who had planned to avenge his dismissal, changes his mind in favor of monetary gain.
He and his aunt, Lady Susan Dowitt, teach Kitty how to pose as a lady of fashion. What Sir Hugh does not count on is the attraction Kitty develops for him. When Hugh is sent to debtors' prison, Kitty charms the wealthy ironmonger Jonathan Selby into marrying her, using part of her dowry to free Hugh. Hugh is furious, but has to accept the situation.
Hugh and Lady Susan soon spend the rest of the dowry and go back into debt. Kitty breaks into her husband's strongbox to get the pair out of debt, but Selby finds out and starts beating her. Seeing this, Kitty's loyal maid kills him, then commits suicide. 
Question: What is the last name of the person who offers to pay someone more to sit for a portrait?
Output (English): Gainsborough.