Question

obsidian hydration dating (ohd), an artifact - dating technique that measures the thickness of the rind that forms on the surface of obsidian (a volcanic glass), can be used to estimate when prehistoric humans used the sharp glass to shape stone tools. the use of ohd requires careful calibration based on a samples climatic context and fluctuations, variations in water vapor pressure, and differences in glass chemistry are known to affect the rate of rind growth. which choice completes the text so that it conforms to the conventions of standard english? a composition, though, b composition, though: c composition; though d composition though

Explanation:

In Standard English, a colon is used to introduce an explanation, list, or elaboration. Here, what follows the blank is an elaboration on how glass - chemistry affects the rind growth. A colon is the appropriate punctuation.

Answer:

B. composition, though: