Final answer:
The chemical indicator should be placed in the most difficult area to sterilize within the basin, which, according to the given information, might be the bottom few inches of the basin's walls.
Step-by-step explanation:
When sterilizing two large basins with smaller bowls in the same set, the chemical indicator should typically be placed in the area that is most difficult to sterilize to ensure the efficacy of the sterilization process. Given Steven's observation that the only part not completely covered are the bottom few inches of the walls of the inside of the basin, one could infer that this might be the area where environmental conditions are least favorable for sterilization. Thus, placing the chemical indicator near this area, maybe above the floor of the basin but below the liquid line, would be advisable. Since Steven indicates that the floor of the basin is completely covered, the next challenging position for sterilization might be the aforementioned bottom few inches of the walls inside the basin. The chemical indicator's position is crucial because if it changes color as intended, it provides evidence that sterilization conditions have been met throughout the basin.