Ascientist wants to study the effects of morning temperatures on flower width.
which is most likely a source of error in this scientific experiment?
a. the distance calipers were recalibrated before each data collection session.
b. the control group flowers were a day older than the experimental group flowers.
c. the measurement units were not converted during the data analysis phase.
d. the flower width data were collected at about the same time every day.

The most likely source of error in the experiment involving the study of the effects of the morning temperatures on the width of the flowers is the fact that the flower kept in the control group were a day older than the experimental flower groups.

The calibration of the calipers before every session will ensure that correct measurement is taken every time. The collection of the width data is also necessary to be taken at the same time so that the same morning temperature is present at the time of width measurement. The use of unconverted units of measurement will have no effect on the experiment results. But the difference in the age of the flowers in the experimental and control groups will alter the experiment results as the width of the older flowers is bound to be different from the younger ones.

Hence, the correct answer is 'Option B - The control group flowers were a day older than the experimental group flowers'.

d. groundwater flows through the subsoil and deposits minerals.