This question focuses on choosing the appropriate word based on context. The context indicates a need for a solution that is valid and acceptable, which is what 'legitimate' means. **Core Concept:** Understanding the meaning of 'legitimate' in a practical context. **Correct Answer Analysis:** Option B, 'legitimate,' is the correct word because it means lawful or acceptable. This fits the context of finding a proper way to solve a problem. **Incorrect Answer Analysis:** - Option A, 'linguistic,' relates to language and is irrelevant to the context. - Option C, 'lest,' means 'for fear that' which doesn't fit the context of finding a solution. - Option D, 'liberal', means broad-minded, which doesn't fit in the context. **Key takeaway:** 'Legitimate' means something that is lawful, fair, or valid, which fits in this context.