What difficulty may arise if the method of an experiment is not written clearly?

Correct answer: Others may not repeat the experiment correctly

The direct answer is D: others may not repeat the experiment correctly. Science depends not only on obtaining a result but also on explaining how the result was obtained. A clear method normally states the materials, measurements, conditions, sequence of steps, and relevant precautions. Step by step: a researcher performs an experiment; if the procedure is not recorded clearly, another person cannot know exactly what was done; different people may use different amounts, times, temperatures, or tools; their results may then differ; so the original finding cannot be checked properly. Option A, “the result will become correct automatically,” is wrong because unclear writing cannot improve the actual experiment or guarantee accuracy. Option B, “all instruments will improve,” is unrelated; instruments do not become better merely because a method is poorly written. Option C, “evidence will increase,” is wrong because missing procedural detail usually weakens the evidence and its reliability. Option D is correct because repeatability requires a sufficiently detailed method. Repetition also helps identify mistakes and test whether a result is dependable. Memory cue: record enough detail so another careful student can perform the same investigation.