Select the option that can be used as a one-word substitute for the given group of words.

The activity of writing dictionaries

Lexicography

"Lexicography" refers to the activity or process of compiling, writing, or editing dictionaries. It involves the study and practice of creating and documenting the meaning, usage, and structure of words in a language. In the given group of words, "the activity of writing dictionaries," the word "lexicography" accurately represents the specific activity of dictionary writing.

"Biography" refers to an account of someone's life written by someone else. It pertains to documenting the life and achievements of individuals, rather than writing dictionaries.

"Bibliography" refers to a list of books or other sources used in a particular work or for research purposes. It involves the compilation of a list of references, not the writing of dictionaries.

"Theology" refers to the study of religious beliefs, principles, and practices. It is unrelated to the activity of writing dictionaries.

Therefore, "Lexicography" is the most appropriate one-word substitute for the given group of words as it directly represents the activity of writing dictionaries and compiling linguistic information.