In a randomised controlled trial, a researcher would like to compare the efficacy in relieving cancer patients' pain of a new pain-killer with placebo. A null hypothesis that there was no difference in pain level between the two groups, and obtained a p-value of 0.038. The researchers would like to publish the findings. Which of the following statement(s) is/are true? 1: At 5% level of significance, the two groups had statistically significant different pain levels. II: It is sufficient to report "p-value < 0.05" without providing the exact p-value. III: Clinical significance of the new pain-killer can be concluded because the p-value is smaller than 0.05. O O O O a. Ill only b. I only c. Il only d. I and III only e. None