We study the problem of identifying defective units in a finite population ofnunits, where unit no.iis independently defective with known probabilitypi. This setting is referred to as theGeneralized Group Testing Problem. A testing procedure is called optimal if it minimizes the expected number of tests. It has been conjectured that, when all probabilitiespilie within the interval [1 − 1/√2, 3−√5/2], thegeneralized pairwise testing algorithm, applied to thepiarranged in non-decreasing order, constitutes the optimal nested testing strategy among all such order-preserving nested strategies. In this work, we confirm this conjecture and establish the optimality of the procedure within the specified regime. Additionally, we provide a complete structural characterization of the procedure and derive a closed-form expression for its expected number of tests. These results offer new insights into the theory of optimal nested strategies in generalized group testing.