The substance used as a fast drying agent in the laboratory is:
A.\[N{a_2}P{O_4}\]
B.${P_2}{O_5}$
C.Charcoal
D.Anhydrous calcium chloride

Hint: The chemical substance used in laboratories to remove the water molecules from the other chemical compounds is known as a drying agent. The drying agents have higher affinity towards the water molecules.

Complete step by step answer:
As we all know that carbon and its derivatives are known as organic compounds. To remove water molecules from these organic compounds some chemicals are used in the chemistry and these chemicals which are used to remove water molecules from the organic compounds are known as drying agents. These chemicals have a tendency to be hydrated, these molecules attract the water molecules towards them and this helps us to remove water molecules from the other compounds. These chemicals allow the other organic compounds to release the water and dry up that’s why these chemicals are known as drying agents.
Some of the drying agents which are used in the laboratories are as follows:
Calcium chloride ($CaC{l_2}$), sodium sulphate ($N{a_2}S{O_4}$), magnesium perchlorate ($Mg{(Cl{O_4})_2}$) and many more are there which acts as drying agents.
The excess of drying agents can harm the hydrated compound, as we discussed above that drying agents have higher affinity towards water molecules so the excess of drying agents will try to capture it all and hence it will absorb the chemical compound as a result. If we use the drying agent a little then it will not absorb all the water molecules from the compound and the water will remain in it making it hydrated. So to make the compound anhydrate the drying agent should be used in the proper amount.
Hence from the above discussion we can conclude that the substance used as a fast drying agent in the laboratory is anhydrous calcium chloride.

So option (D) is correct.

Note:
The drying agents are mostly used for organic compounds in organic laboratories and anhydrous calcium chloride is the best drying agent for laboratory use. Mostly organic compounds are immiscible in water but due to polarity they trap some water molecules and hence to remove the water molecules we use drying agents.