Answer:
A. Yes, the substance must be water.
Step-by-step explanation:
The density of a substance is unique to it. Density is defined the as the amount of substance contained per volume.
One of the ways of identifying a substance is to determine its density. Every matter is known to have their own specific densities. This makes them different from other substances. The density of gold is unique to it and it differs from that of silver.
In fact, water has density of 1.00gcm⁻³. Experimental errors and some little factors must have altered our expected figure. This a case of precision and accuracy in the experiment.