Final answer:
Option 3) is correct answer. A cilium is the structure that has a 9 + 2 microtubule arrangement, which is a pattern consisting of nine outer doublets and two central microtubules.
Step-by-step explanation:
The structure with a 9 + 2 microtubule arrangement is a cilium. This arrangement consists of a ring of nine microtubule doublets surrounding a pair of central microtubules. Basal bodies, which are similar to centrioles, serve as the foundation for cilia and flagella and provide the anchoring site where the 9 + 2 structure forms. Although a centriole is involved in the organization of microtubules during cell division, it does not have this specific 9 + 2 pattern as it is made up of nine triplets of microtubules.