You are reading a research report in a peer-reviewed journal where the nurse investigator states the following,

An experimental design was used to investigate the mean Vitamin D level among a control group of patients and an experimental group of patients in a Covid-19 ICU. The control group was not given supplemental Vitamin D and the experimental group was given supplemental Vitamin D on admission. The dependent variable was the mean number of days on ventilation.

The following hypotheses were provided in the research report,

H0: There is no difference in the mean ventilator days among patients who receive Vitamin D supplementation on admission and patients who do not receive Vitamin D supplementation on admission to a Covid-19 ICU.

H1: There is a difference in mean ventilator days among patients who receive Vitamin D supplementation on admission and patients who do not receive Vitamin D supplementaiton on admission to a Covid-19 ICU.

When developing the research study, which of the following is the statistical analysis the nurse investigator stated in the methodology section?