Genus-recall approach:
Rather than matching one item at a time, group the four common names by their botanical genus first: Canavalia (sword bean), Coccinia (ivy gourd), Vigna (cowpea) and Trichosanthes (snake gourd) are four distinct and well-known genera among Indian vegetable crops. Recalling the species names directly, Canavalia gladiata is sword bean, Coccinia indica (syn. grandis) is ivy gourd, Vigna unguiculata is cowpea, and Trichosanthes anguina is snake gourd. Slotting these fixed pairs against the List-II order given in the question reproduces the sequence sword bean-(IV), ivy gourd-(III), cowpea-(II), snake gourd-(I).