Answer: a TV program about the artwork of Osamu Tezuka
Step-by-step explanation:
A website that teaches to make manga with a computer would probably provide information on programming, rather than in the history of manga. Dragon Ball or Sailor Moon are works of fiction, with no content related to Carlos' research, so they wouldn´t be useful for him. Given that he wants to see manga from the 20th century, a video about Japanese art in the 1100s would not be useful either. Only a TV program about Osamu Tezuka, who is famous for his manga from post-World War II Japan would provide Carlos with the information he wants.