Answer
Excited state
Work Step by Step
We know that the atom is in an excited state because the ground state electronic configuration of potassium is $1s^2 2s^2 2p^6 3s^2 3p^6 4s^1$ but the given electronic configuration is $1s^2 2s^2 2p^6 3s^2 3p^6 3d^1$. We know that the 3d state is higher than the 4s state, hence the atom is in an excited state.