This question evaluates the understanding of the term 'therefore' and its use in academic writing. 'Therefore' is used to introduce a conclusion based on previous statements. Option B is correct because it uses 'therefore' to conclude that further research is needed due to inconclusive results. Option A is incorrect because it uses 'therefore' to introduce a method, not a conclusion. Option C is incorrect because it suggests a general statement rather than a conclusion. Option D is incorrect because it merely states a sequence of actions without drawing a conclusion.