Which statement is an observation, not an inference?

• A. The plant grew 3 cm in one week
• B. The plant looks healthier
• C. The plant needs more fertilizer
• D. The plant requires more sunlight

Answer: (A)

Observations are things you can verify with data or direct noticing. Measuring a plant’s growth over time is a direct, verifiable fact. Saying the plant grew 3 cm in one week reports a specific change you can check with a ruler, so it’s an observation. The other statements involve interpreting the plant’s condition or needs—judging health from appearance or inferring what the plant requires—based on reasoning beyond the measured data. Those are inferences rather than observations. So, the growth of 3 cm in a week is the observation.