Identify the element corresponding to the electron configuration [Kr] 5s^2 4d^1.

The given electron configuration [Kr] 5s² 4d¹ can be broken down to understand the element it represents. The notation [Kr] signifies that the configuration includes the noble gas krypton, which accounts for the filled inner electron shells. After krypton, the configuration continues with 5s², indicating that there are two electrons in the 5s orbital. Following that, there is one electron in the 4d orbital.

To determine the elemental identity from this configuration, we can add up the total number of electrons. Krypton has 36 electrons, and by adding 2 for the 5s electrons and 1 for the 4d electron, we arrive at a total of 39 electrons. This electron count corresponds to the element yttrium (Y), which is located in period 5 of the periodic table.

Yttrium is known for having an electron configuration ending in 4d¹, confirming that the correct answer is indeed yttrium. The other options represent elements with different numbers of electrons, which do not match the calculated total and hence do not correspond to the provided electron configuration.