A student performed an experiment to determine the molecular formula of a given sample of hydrated copper (II) sulphate by weighing the sample before and after heating. The formula obtained experimentally was $$CuSO_4 \cdot 5.5H_2O$$ while the actual formula of the given sample is $$CuSO_4 \cdot 5H_2O$$. Which experimental error would account for the wrongly obtained result?

A

During heating, some of the hydrated copper (II) sulphate was lost

B

The hydrated sample was not heated long enough to remove all the water present

C

Weight of the hydrated sample recorded was less than the actual weight taken

D

The balance used in the study showed all weights consistently high by 0.10 g