The most significant difference between the northern and southern Carolina settlements was that

a the southern settlement attracted settlers from England while the Northern settlement attracted settlers from Virginia
b the Southern settlements grew rich on rice while poorer farmers in the North grew tobacco
c the Northern settlement was free of slavery while the Southern settlement relied on enslaved workers
d the Southern settlement was more loyal to English nobles than the Northern settlement

c the Northern settlement was free of slavery while the Southern settlement relied on enslaved workers

The most significant difference between the northern and southern Carolina settlements was:

c) The Northern settlement was free of slavery while the Southern settlement relied on enslaved workers.

To find the answer to this question, we need to compare the characteristics of the northern and southern Carolina settlements. Let's go through each option one by one:

a) The option states that the southern settlement attracted settlers from England, while the northern settlement attracted settlers from Virginia. However, this is not a significant difference between the two settlements.

b) This option suggests that the southern settlements grew rich on rice while the poorer farmers in the north grew tobacco. This is indeed a significant difference between the two regions as their economic activities varied.

c) The option states that the northern settlement was free of slavery, while the southern settlement relied on enslaved workers. This is a key distinction between the north and south and a significant difference in terms of labor practices and social structure.

d) This option suggests that the southern settlement was more loyal to English nobles than the northern settlement. While loyalty to English nobles might vary, it is not a significant difference that defines the two settlements.

Based on the analysis above, the correct answer is option c) the northern settlement was free of slavery while the southern settlement relied on enslaved workers.