The 9 plus 2 array of a eukaryotic flagellum consists of which arrangement?

1. Flagella and cilia differ in length and number but share one structural arrangement of microtubules. 2. That arrangement is called the 9 plus 2 array. 3. A single flagellum or cilium is made of a ring of nine microtubule doublets. 4. Those nine surround a single microtubule doublet at the center. 5. Nine triplets in a cylinder describes a centriole instead, so that answer names the wrong structure. 6. The array is nine doublets around one central doublet. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 4 "Cell Structure", section 4.5 The Cytoskeleton_