Final answer:
Most poets rebelled against strict structural guidelines and instead embraced free verse when writing poems that emphasized the importance of nature.
Step-by-step explanation:
Most poets rebelled against A) Strict structural guidelines when writing poems that emphasized the importance of nature. They sought to break free from the traditional forms of poetry and instead embraced D) Free verse. Free verse allows poets to create their own structure without adhering to strict rules of meter and rhyme. This form of poetry emphasizes thematic, syntactic, or semantic repetition and development to create coherence.