Correct Subject-Verb Agreement

In an effort to improve community engagement, the mayor proposed a series of initiatives designed to enhance local participation; however, the council members were divided about whether they could effectively implement these plans. The proposed initiatives include increased funding for community centers, broadening access to public services, and establishing regular town hall meetings.
Choose the option that best enhances the clarity and grammatical correctness of the following sentence:

One of the council members _____ concerned that the proposals might not address the core issues facing the community.