Final answer:
The BEST interpretation of the message in the given sentence is that the Georgia Legislature would have stopped children from working in the mills if women could vote.
Step-by-step explanation:
The BEST interpretation of the message in the given sentence is:
D) The Georgia Legislature would have stopped children from working in the mills if women could vote.
This interpretation is supported by the fact that the sentence is framed as a hypothetical question. It suggests that if mothers and teachers in Georgia had the right to vote, the Georgia Legislature would have taken action to stop child labor in the mills. This implies that currently, the legislature has not taken such action, indicating that children are working in the mills.