Final answer:
The correct pair of homonyms from the options given is 'a. bald and bawled' as they have the same pronunciation but different meanings, making them true homonyms.
Step-by-step explanation:
The question is asking which pair of words are homonyms. Homonyms are two or more words that have the same spelling or pronunciation but different meanings and origins.
In the provided options, the correct pair of homonyms is a. bald and bawled. The word bald refers to lacking hair, while bawled means to have cried or shouted loudly; they sound the same but have different meanings.
The other options, pairs b, c, and d, do not consist of homonyms because the words do not have the same pronunciation and/or spelling.