Final answer:
Line C from the options provided includes evidence about homework's effect on academic performance by referencing a study, while other lines mention assertions without direct empirical support.
Step-by-step explanation:
Among the lines provided, line C: but the study also found that larger amounts homework did not improve the kids' performance includes evidence. This line references a study, which is a form of empirical evidence, and directly relates to the impact of homework on performance, indicating a research-based finding. The other lines, A, B, and D, express claims or opinions that may hint at evidence but are not directly presenting a research finding or data. The inclusion of a study in line C strengthens the argument with researched data rather than anecdotal or speculative information.