Answer:
Articles are typically not capitalised.
Explanation:
From option a through d, only terms categorised in option a are typically not capitalised.
One of the common title capitalisation practice is that unless the articles are the first word or the last word, they are not capitalised.
Examples of articles are "the", "a" and "an"
Consider the following statement:
The Portrait of A Young Man
This would be regarded as a wrong capitalisation practice not because of the "the" but because use of uppercase "A" in place of a lowercase "a"
A good example of common title capitalisation practice would be
The Sense of an Ending