Prior to the intellectual revolutions of the 18th century, two of the primary assumptions of Western thought regarding the origins and development of humankind were:

A. The fixed (immutable) nature of all living creatures and man's dominance of nature (great chain of being).

B. The variation in nature was caused by genetic mutation and living organisms change over time.

C. Intelligent design and Lamarckian evolution.

D. Cultural relativism and disequalibrium.

Correct answers are A and C

Explanation:

A. The "great chain of being" is a medieval concept, a hierarchal structure of matter and living organisms promulgated by Christianity, which put God on top of it all: first God (spirit form), then humans (matter and spirit), then animals and plants (only matter).

B. The concept of "genetic mutation" belongs to de 19th century, when Gregor Mendel started studying genetics as a science. Even though inherit traits had been observed before him, he was the first one to analyze them though a modern science approach.

C. Inherit traits have been observed by many before the 18th century. Aristotle, for example, observed the animal's structure changed according to their feeding routines or where they lived (Darwin, for example, then observed those traits but developed the theory of evolution). Lamarck fathomed the concept of "soft inheritance" but it had been around since the classical era.

D. Cultural relativism is a concept that was originated later on, in the 20th century.

So, we can rule out B and C because of temporal timeline (concepts developed after the 18th century), whereas A and C mention ideas that belong to medieval and classical ages.