Final answer:
The correct shorthand for the configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s² is d. [Kr]5s², as it builds upon the noble gas krypton's configuration.
Step-by-step explanation:
The correct shorthand notation for the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s² is [Kr]5s². This is because the electron configuration up to the 4p⁶ level is equivalent to the electron configuration of krypton (Kr), a noble gas. The remaining part, 5s², shows that there are two more electrons in the 5s orbital after the krypton core configuration. Thus, the correct answer is option d. [Kr]5s².