The scenario that best illustrates the Fraud Triangle component known as "perceived opportunity" is when duties are not properly segregated. In the absence of proper segregation of duties, individuals may find it easier to commit fraud because controls that would normally prevent or detect improper actions are weak or nonexistent. This creates an opportunity for fraud to occur, which is a key element of the Fraud Triangle.
References: Institute of Internal Auditors (IIA) - International Professional Practices Framework (IPPF)