Definition: In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
Input: Passage: The bottom section of Tilden's "promontory" extension, the dining room contains the original suite of table and dining chairs designed by Heal's to Churchill's exacting requirements – (see box). An early study for a planned picture by William Nicholson entitled Breakfast at Chartwell hangs in the room. Nicholson, a frequent visitor to Chartwell who gave Churchill painting lessons, drew the  study for a finished picture which was intended as a present for the Churchills' Silver Wedding anniversary in 1933 but, disliking the final version, Nicholson destroyed it. The picture depicts the Churchills breakfasting together, which in fact they rarely did, and Churchill's marmalade cat, Tango. The tradition of keeping a marmalade cat at Chartwell, which Churchill began and followed throughout his ownership, is maintained by the National Trust in accordance with Churchill's wishes. In a letter to Randolph written in May 1942, Churchill wrote of a brief visit to Chartwell the previous week, "the goose and the black swan have both fallen victim to the fox. The Yellow Cat however made me sensible of his continuing friendship, although I had not been there for eight months".Above the dining room is the drawing room and, above that, Lady Churchill's bedroom, described by Churchill as "a magnificent aerial bower". 
Question: What is the first name of the person who is a frequent visitor to Chartwell?

William.