According to the "Hands-On" Case at the End of the Chapter

According to the "Hands-On" case at the end of the chapter, why was October 29, 1998, a historic day for advertising?

A) It was the first time that the cost of a 30-second ad during a prime time television program exceeded $1 million.
B) Five live-action, rather than taped, commercials aired during the network coverage of John Glenn, the then 77-year-old former astronaut and senator who returned to space aboard the space shuttle.
C) The first five TV commercials ever broadcast in high definition (HDTV) occurred that day.
D) The percentage of households with HDTV-ready sets reached a threshold of 30 percent.
E) All advertising commercials switched to HDTV format in the anticipation of the looming explosive growth the HDTV-ready television sets among consumers.