Question

Which of the five categories (a,b,c,d,e) do the following irregular noun plurals fall into?
mouse,kangaroo,woman,mosqito,fish,hand -kerchief,zoo,elf,bath,self,path,hoof,Eskimo,Vietnamese,volcano,oath

Answer 1

a -- oaths, paths, baths, zoos, kangaroos, Eskimos
b -- hooves, selves, elves, hand-kerchieves
c -- volcanoes, mosqitoes
d -- women, mice
e -- Vietnamese, fish 

Answer 2

mouse- a, kangaroo- a/c, woman-d, mosquito-c, fish- c, hand- a, kerchief- a, zoo-a, elf-b, bath-c, self-a/b, path-b/d, hoof-b, Eskimo- a, Vietnamese-a, volcano-c, oath-a. 
Там где стоит / - это значит или, а не и то и то.