Elimination approach:
Option (B), "ISMP #3", is not a recognised phytosanitary code at all, being a transposed misspelling of ISPM, so it can be discarded outright. Among the genuine ISPM numbers, ISPM #2 deals with the framework for pest risk analysis, and ISPM #5 is simply the glossary of phytosanitary terms used across the standards, neither of which specifically governs the safe movement of biological control organisms.
ISPM #3, by contrast, is the International Standard for Phytosanitary Measures that lays down guidelines for the responsible import and release of biological control agents and other beneficial organisms, which is precisely what classical biological control, the introduction of exotic natural enemies against invasive pests, depends on.
Eliminating the invalid and unrelated options leaves ISPM #3 as the correct match.