A. Most Rishonim, as well as most of the major poskim, agreed with Tosafot's approach.
Rice is considered the most nutritious of all known grains.
It is unclear whether the Beit Yosef prefers the Rosh's resolution or Rabbeinu Yona's. It is interesting to note that, as he records the different sides of the dispute, the Beit Yosef does not factor in the simple reading of the Rambam. This point becomes relevant to the determining his halakhic position because his wording of the Shulchan Arukh about rice is an exact quote of the Rambam. However he understood it, the Rambam's approach was the Shulchan Arukh's final decision on this matter. This also seems to be the straightforward reading of the Rambam.