Step 1: Concept
Pre-fertilization barriers are reproductive isolations that prevent the formation of a zygote (e.g., pollen-stigma incompatibility).
Step 2: Analysis
Embryo rescue is a post-fertilization technique used when a zygote forms but would otherwise abort.
Step 3: Meaning
Protoplast fusion (Somatic Hybridization) bypasses the sexual fertilization process entirely. By fusing the vegetative cells of two different species, you can create a hybrid without needing successful pollination or fertilization.
Step 4: Conclusion
Thus, protoplast fusion is the primary method to overcome pre-zygotic/pre-fertilization barriers.
Final Answer: (B)