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How long is a light year?

  1. 3.26 years

  2. 3.26 months

  3. 3.26 weeks

  4. 3.26 days

The correct answer is: 3.26 years

A light year is a unit of measurement used in astronomy to measure vast distances. It is the distance that light travels in one Earth year, which is approximately 9.46 trillion kilometers. Therefore, the answer cannot be B, C, or D as they all indicate significantly shorter periods of time and would not equate to the immense distance of a light year. The time measurement of 3.26 years as the light year's equivalent is the only viable option given the definition.