Final answer:
The techniques of examining clients' memories and focusing on interpretation are most closely associated with Psychoanalytic therapy, which makes D) Psychoanalytic therapy the correct answer for the question.
Step-by-step explanation:
The techniques in question belong to different schools of psychotherapy. Emphasizing clients' strengths is a common aspect of Client-Centered therapy, which was developed by Carl Rogers. The examination of clients' memories and focusing on interpretation are often associated with Psychoanalytic therapy, which originated with the work of Sigmund Freud. The phrase 'spitting in the client's soup' is more metaphorical and less commonly referenced, but it relates to an intervention style that could be more confrontational or unexpected, possibly aligning with therapy styles that challenge clients' perspectives, such as in some forms of existential therapy.
Given the choices, A) Existential therapy, B) Rational Emotive Behavior Therapy (REBT), C) Person-Centered therapy, and D) Psychoanalytic therapy, the answer is D) Psychoanalytic therapy. This is because interpreting memories and focusing on interpretation are hallmark techniques of psychoanalysis.