Question: Which of Apple's products is focused on the ultraportable niche of PC's?
Sentence: While sales of the Macintosh have largely held steady, in comparison to Apple's sales of the iPhone and iPad which increased significantly during the 2010s, Macintosh computers still enjoy high margins on a per unit basis, with the majority being their MacBooks that are focused on the ultraportable niche that is the most profitable and only growing segment of PCs.
Answer in sentence: yes