Leave the container and the glass uncovered for two days on the kitchen counter or on the dining table. After two days, carefully measure the water in each container using the measuring cup. Record your findings. HELP

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 the same spin.

The answer to the question is d