A researcher studying time and motion measures how long it takes the nurse to do a particular task. ...

ANS: D
Ratio-scale measurement, the highest form of measurement, has an absolute zero point. This means the value of zero indicates the absence of the property being measured. In this case because the researcher is collecting data in units of time and it is possible that the nurse takes zero minutes to perform a task, we determine time is measured at the ratio level.
When measuring the amount of time something takes, it can take zero minutes therefore it is a higher measurement than interval.
Minutes would not imply names categories, which is nominal data.
Minutes do more than rank order the data.