Final answer:
When writing gender-neutral business correspondence, it is advisable to use 'they,' 'them,' and 'their' as singular pronouns or opt for gender-free nouns like 'person' or 'individual.'
Step-by-step explanation:
When writing gender-neutral business correspondence, the best approach is to use plural pronouns or 'gender-free' nouns. Specifically, option c) choose singular pronouns refers to the modern practice of using 'they,' 'them,' and 'their' as singular pronouns when the person's gender is unknown, unimportant, or when they have indicated a preference for non-gendered pronouns. This practice avoids gender bias and includes people who identify outside the gender binary. Another approach is to use a person's name or to opt for gender-free nouns like 'person,' 'individual,' or 'child' to maintain neutrality.