Final answer:
The sublevel in question is the 3d sublevel, filling after the 3p and 4s sublevels, and before the 4p sublevel. It is one principal energy level behind, typically starting to fill during the fourth period of the periodic table.
Step-by-step explanation:
The sublevel depicted must be determined by the contexts such as energy levels and their order of filling. The d sublevel is one principal energy level behind, implying that the 3d sublevel will first fill during the fourth period, which is after the 3p sublevel and the 4s sublevel. Since the 4f sublevel does not fill until just after the 6s sublevel and is always two principal levels behind, we can conclude that the option B) 3d represents the sublevel in question. This is corroborated by the fact that the 4f sublevel is associated with the sixth period and begins filling after the 6s sublevel, following the general rule for f sublevels.