Identifying Internal Attribution

Attribution Theory is a concept within social psychology that explores how individuals explain the causes of behavior and events. When observing someone's actions, we might infer that their behavior is due to either internal characteristics or external situations. For example, if a student fails a test, we could attribute this outcome to their lack of preparation (an internal attribution) or to the test being exceptionally difficult (an external attribution).

Which of the following best defines the term 'internal attribution'?