The atomic number of an element corresponds to the number of protons in the nucleus of its atoms. In the case of the question you mentioned, the correct answer is 26, which corresponds to iron (Fe).
While both titanium (Ti) and iron (Fe) have 4 electrons in their 3d subshells, the difference lies in their electron configurations.
The electron configuration of titanium is [Ar] 3d^2 4s^2. This means that in its ground state, two of the four electrons in the 3d subshell of titanium are paired, while the other two are unpaired. Therefore, titanium does not fulfill the condition of having 4 unpaired electrons.
On the other hand, the electron configuration of iron is [Ar] 3d^6 4s^2. In the ground state of iron, there are six electrons in the 3d subshell, and all of them are unpaired. Thus, iron satisfies the requirement of having 4 unpaired electrons.
Therefore, the correct answer to the question is 26, corresponding to iron (Fe), not 22.