Which 20th-century artist used tempera to create the painting that gentleman? jasper johns jacob lawrence andrew wyeth pablo picasso georgia o'keeffe?

I believe the correct answer is: Andrew Wyeth.

Andrew Newell Wyeth was the best known American visual artist, primarily a realist painter, working predominantly in a regionalist style in 20th-century. He was the artist used tempera to create the painting "That Gentleman" in 1960, which portrays an elderly African-American man named Tom Clark, who was the neighbor of Wyeth.