Answer:
d. the essential nature of an experience.
Step-by-step explanation:
Descriptive phenomenology is given as precursor to Karl Jaspers, and according to Jasper the initial task of "subjective psychology" should be precisely to distinguish subjective phenomena, to describe and name them, always in search of the essential nature of an experience.
Only in this way would the approach to subjectivity go from being merely a sharing of experience to becoming systematizable, communicable, and testable knowledge. This would characterize phenomenology itself, as it conceived. In this sense, Jaspers suggests descriptive psychopathology or phenomenology as a fruitful program and calls for explorations in the area.