Final answer:
Strontium Nitrate (Sr(NO₃)₂) will not conduct as a solid but will conduct if dissolved in water.
Step-by-step explanation:
Substance B, Strontium Nitrate, will not conduct as a solid but will conduct if dissolved in water. This is because solid ionic compounds, such as Strontium Nitrate, do not conduct electricity. However, when these compounds dissolve in water, they dissociate into ions and form an aqueous solution, which can conduct electricity.