The correct answer is option 'A' - Pedantic.

Explanation:

Pedantic refers to a style in which a writer makes a display of his knowledge. Let's understand the meaning of each option and why option 'A' is the most suitable substitute for the given word/sentence.

a) Pedantic: This word refers to someone who is overly concerned with minor details and rules, often showing off their knowledge in a pompous or pretentious manner. In the context of the question, a writer who uses a pedantic style is someone who excessively displays their knowledge.

b) Verbose: This word means using more words than necessary or being wordy. While a verbose writer may use an excessive amount of words, it does not necessarily indicate a display of knowledge. Therefore, this option is not the best substitute for the given word/sentence.

c) Pompous: Pompous refers to someone who is arrogant, self-important, and excessively showy in their behavior or speech. Although a pompous writer may display their knowledge, this word does not specifically convey the idea of a writer making a display of their knowledge. Thus, it is not the most suitable substitute in this context.

d) Ornate: This word means elaborately or excessively decorated or adorned, especially in writing or speech. While an ornate writing style may involve using complex or decorative language, it does not necessarily imply a display of knowledge. Therefore, this option is not the best substitute for the given word/sentence.

In summary, the word 'pedantic' best fits the meaning conveyed in the given word/sentence. It describes a style in which a writer excessively displays their knowledge, making it the most suitable substitute among the given options.