Which set of three words do not all rhyme with each other?
A) Gilt/guild/gilet
B) Holy/wholly/ holey
C) Caw/corps/core
D) Pare/pair/pear

Hint: Words that have similar pronunciation or rhyme with each other are called homophones. For e.g. weather and whether. Such words only have a similar sound. Their spellings may or may not be similar, but their meanings and definitions will definitely be different.

Complete answer:
To choose the correct option we shall look at each word in one option and check their pronunciation. If at least two words have the same pronunciation, we will rule out that option.
Option A) Gilt/guild/gilet – In this option both ‘gilt’, and ‘guilt’ are pronounced as ‘gilt’. Whereas ‘gilet’ as ‘giley’. Two of the words rhyme in this option. Therefore, this option is incorrect.
Option B) Holy/wholly/ holey – The words ‘holy’ and ‘holey’ have the same pronunciation, though ‘holey’ is an incorrect word. ‘Wholly’ has a slightly different pronunciation. Two of the words in this option rhyme with each other. Thus, this option is wrong.
Option C) Caw/corps/core – All three words in the option, i.e. caw, corps and core, have different pronunciations from each other. Therefore, this option is correct.
Option D) Pare/pair/pear – In this option, all the words have the same pronunciation, i.e. rhyme with each other. Therefore, this option is also wrong.

Thus, the correct answer is option (C) Caw/corps/core.

Note: Some words have the same sound and even the same spelling, but still they have different meanings. Such words are called Homonyms. For e.g. there is no light in this room. (opposite of dark). This box is very light. (opposite of heavy). Such words can only be differentiated when they are used in some specific context.