Which word best completes the sentence: She decided to be ________ during the meeting to share her ideas?

The word that best completes the sentence is "assertive." This choice is effective because it conveys the idea of being confident and willing to express one’s thoughts and ideas clearly during the meeting. Being assertive implies taking an active role in the discussion, which aligns with the intention to share ideas.

In contrast, the other options do not fit the context of the sentence. "Quiet" suggests a lack of vocal participation, which contradicts the goal of sharing ideas. "Passive" also implies a lack of responsiveness or involvement, which is not what the sentence is aiming to express. Lastly, "indifferent" indicates a lack of interest or concern, making it unsuitable since the person clearly wants to engage and contribute during the meeting. Therefore, "assertive" is the most fitting choice for someone who intends to be proactive in sharing ideas.