Is it chapter or something else?
An aphorism is A. a short saying with a message.
It is an observation that contains some general truths.
Annotations are like small notes of explanation or a comment added to a text or diagram.
The correct answer is B. subjective.
In order to complete this sentence, you need to use a subjective pronoun. That pronoun would be SHE, as in - '... she decided to train for the marathon herself.' An objective pronoun would be HER, which is obviously incorrect. An intensive and a reflexive pronouns look the same - HERSELF. As a matter of fact, there is an intensive pronoun in the sentence above - the last word.