In which all have d¹⁰ configuration in their ground state?

The correct option is Cu, Zn, Cd, Ag.

To determine which set of elements all have a $d^{10}$ electronic configuration in their ground state, let us write down the electronic configurations of the transition elements in the options:

1. Copper (Cu, Z = 29):
The expected configuration is $\left[\mathrm{Ar}\right]3d^{9}4s^2$. However, due to the extra stability of a fully-filled d-subshell, one electron from the $4s$ orbital transitions to the $3d$ orbital. Thus, the ground-state configuration is:
$\left[\mathrm{Ar}\right]3d^{10}4s^1$
This has a $d^{10}$ configuration.

2. Zinc (Zn, Z = 30):
The ground-state electronic configuration is:
$\left[\mathrm{Ar}\right]3d^{10}4s^2$
This has a $d^{10}$ configuration.

3. Silver (Ag, Z = 47):
Similar to copper, silver belongs to group 11 and exhibits an anomalous configuration to achieve a stable fully-filled d-subshell. The ground-state configuration is:
$\left[\mathrm{Kr}\right]4d^{10}5s^1$
This has a $d^{10}$ configuration.

4. Cadmium (Cd, Z = 48):
Cadmium belongs to group 12 (below zinc) and has a completely filled d-subshell. The ground-state electronic configuration is:
$\left[\mathrm{Kr}\right]4d^{10}5s^2$
This has a $d^{10}$ configuration.

Since all four elements (Cu, Zn, Cd, Ag) possess a $d^{10}$ configuration in their ground state, they satisfy the requirement.