Titanium has an atomic number of 22. the following orbital notation for titanium is incorrect. explain the error in terms of the rules for electron arrangements.
titanium:

The problem here is that according to Aufbau Principle before 3d orbital 4s subshell comes.After filling 3p orbital with electrons you have 4 electrons left,you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with same spin.

A.(nh4)(2co3)is the correct answer