Final answer:
The element that corresponds to the electron configuration 1s^22s^22p^63s^23p^64s^13d^5 is vanadium (option a).
Step-by-step explanation:
The electron configuration 1s22s22p63s23p64s13d5 corresponds to vanadium (option a).
In the ground state, the electron configuration of vanadium is 1s22s22p63s23p64s23d3. However, when an electron is removed from the 4s orbital, it leaves the configuration 1s22s22p63s23p64s13d5, which matches the given electron configuration.