Phalaenopsis, commonly known as moth orchids, are highly popular and commercially significant pot plants. In the Dutch Auction of 2012, Phalaenopsis was the principal pot plant sold due to its attractive flowers, long blooming period, and demand in international markets.
(A) Rose: Mostly sold as cut flowers rather than pot plants in auctions.
(B) Chrysanthemum: Popular flower but less dominant in the Dutch pot plant auction.
(C) Kalanchoe: A pot plant but not the principal one in this auction.
(D) Phalaenopsis: Correct. Principal pot plant sold in the Dutch Auction, 2012.