Final answer:
The most appropriate test to use is the Chi-Square test to check the relationship between practicing a religion and having a do-not-resuscitate order for terminally ill patients.
Step-by-step explanation:
The most appropriate test to use to check whether there is a significant relationship between whether terminally ill patients practice a religion and whether they have a do-not-resuscitate order is the Chi-Square test. The Chi-Square test is used to determine if there is a significant association between two categorical variables. In this case, the two variables are practicing a religion (yes/no) and having a do-not-resuscitate order (yes/no).