Final answer:
Anthropologists in the 19th century typically a) classified cultures based on subsistence patterns.
Step-by-step explanation:
During the 19th century, anthropologists exhibited certain characteristics in their studies. They often classified different cultures based on subsistence patterns, which refer to the ways in which societies obtain food. Additionally, it is incorrect to say that they did not have a system for classifying different cultures. They did have systems, such as the evolutionary scheme proposed by Edward Tylor, which assigned cultures to different stages of development. Therefore, the correct answer is a) They usually classified different cultures on the basis of subsistence patterns.