The correct answer is: Self-actualisation
Rationale: According to Maslow, self-actualisation is the final 'need' to be satisfied. It is the fulfilment of personal potential. Maslow claims that this can rarely be satisfied.
Ways in: It might be worth memorising the triangular diagram and perhaps adding pictures to help you remember.
Pitfalls: You may have hesitated over self-realisation but this was just a fictitious distracter. Esteem needs and physiological needs are lower down the hierachy.