In which of the following types of texts is denotative language most likely to dominate the author’s writing?
a)a movie review
b)an advertisement for medicine
c)an introductory textbook on astronomy
d) a presidential inaugural address

C) An introductory textbook on astronomy.

Explanation: the denotation of a word is its literal meaning, the definition that we can find in a dictionary, a word can have several denotations (or definitions). It is the contrary to connotation which is the meaning given by the context or even by the readers (or listeners) based on their emotions or personal experiences. From the given options, the one that will most likely be dominated by denotative language, is an introductory textbook on astronomy, because it will need to use the actual definitions of the words to explain the subject.