based on the last image i sent answer this:

(d) Explain two different things that the researchers could have done to obtain a narrower interval than the one you found in part (b). (Select all that apply.) O The researches could have used a smaller sample size. The researches could have used a higher confidence level. The researches could have used a lower confidence level. The researches could have used a larger sample size. The researchers could have selected a larger value of (x1 - x2). O The researchers could have selected a smaller value of (x1 - x2). You may need to use the appropriate table in the Appendix of Tables to answer this