Final answer:
Before the 20th century, tree-ring analysis was the primary method for dating archaeological materials precisely. Dendrochronology and radiocarbon dating became critical absolute dating methods in the 20th century for establishing dates in archaeology.
Step-by-step explanation:
Before the development of scientific absolute dating methods in the 20th century, the main way to connect exact dates to archaeological materials was using tree-ring analysis. This method, also known as dendrochronology, involves measuring the width of tree rings to determine the age of wood used in ancient structures. It relies on the annual formation of growth rings in trees, which can be correlated across different samples to establish a precise timeline. Radiocarbon dating is another absolute dating technique that became prevalent in the 20th century; it uses the decay of carbon-14 to date organic materials.
Answer: C) 20th; tree-ring analysis