Step 1: Sentence Analysis.
The sentence discusses a New Year's action or commitment. The term "resolution" is standard for New Year's resolutions, denoting a firm decision or commitment for the upcoming year.
Step 2: Conclusion. The appropriate word is "resolution," aligning with the context of a New Year's decision. Consequently, the correct option is 3. resolution.
Final Answer: \[\boxed{\text{The correct answer is 3. resolution.}}\]