罗克韦尔（Rockwell）自动化公司将可持续生产定义为更清洁、更安全、更节能的生产。（sustainable）

Norman Rockwell was a meticulous artist (who) paintings (portrayed) family incidents and well-defined (characters) with a wealth of supporting (details).（） A: who B: portrayed C: characters D: details

What is the main purpose of this conversation A: The use of photographs in painting. B: The TV program about Norman Rockwell. C: The Saturday Evening Post magazine. D: Exhibits of art on magazine covers.