Copper sulphate solution can be safely kept in a container made of

The correct option is C

silver

The explanation for the correct option C:

• Arrangement of the metals on the basis of their reactivity towards other elements is termed as activity series. The activity series in decreasing order is:

$\mathrm{K}>\mathrm{Na}>\mathrm{Li}>\mathrm{Ba}>\mathrm{Sr}>\mathrm{Ca}>\mathrm{Mg}>\mathrm{Al}>\mathrm{Mn}>\mathrm{Zn}>\mathrm{Cr}>\mathrm{Fe}>\mathrm{Cd}>\mathrm{Co}>\mathrm{Ni}>\mathrm{Sn}>\mathrm{Pb}>\mathrm{H}>\mathrm{Sb}>\mathrm{Bi}>\mathrm{Cu}>\mathrm{Hg}>\mathrm{Ag}>\mathrm{Au}>\mathrm{Pt}$

• Elements at the starting of this series are comparatively more reactive than elements present after them in the series.
• In a single displacement reaction, an element from its compound is substituted by another element to form two product molecules. Elements that are more reactive according to the activity series can displace the elements less reactive than them from their compounds.
• Since Silver (Ag) is less reactive than Copper (Cu) in the activity series, Silver (Ag) cannot displace Copper (Cu) from Copper sulfate $\left({\mathrm{CuSO}}_4\right)$. Hence, no reaction occurs between Silver (Ag) and Copper sulphate and copper sulphate can be stored in Silver (Ag).

The explanation for incorrect options:

Since Aluminium (Al), Lead (Pb) and Zinc (Zn) are more reactive than Copper in the activity series, these elements can displace Copper (Cu) from Copper sulfate.

Final Answer: Hence, option C is correct. Copper sulphate can be kept in Silver.