Let's examine the diseases and their causative organisms:
Filariasis (A): The causative organism for filariasis is Wuchereria bancrofti , which is a parasitic worm. This is a correct match for I .Malaria (B): The causative organism for malaria is Plasmodium vivax , which is a protozoan parasite. This is a correct match for III .Amoebiasis (C): The causative organism for amoebiasis is Entamoeba histolytica , which is a protozoan parasite. This is a correct match for IV .Pneumonia (D): The causative organism for pneumonia is Haemophilus influenzae , which is a bacterium. This is a correct match for II .Thus, the correct matches are:
Disease Causative Organism Match Filariasis Wuchereria bancrofti A - I Malaria Plasmodium vivax B - III Amoebiasis Entamoeba histolytica C - IV Pneumonia Haemophilus influenzae D - II
Therefore, the correct option is Option (3).