Answer:
C. Change "don't have the money" to "do not make enough profit."
Step-by-step explanation:
A formal tone is a style of speaking or writing in a polite, and more proper manner, that often contains descriptive, precise and elegant words, longer sentences and it is totally free from idioms, colloquialism, slang, and contractions. Thus, when making the change of "don't have the money" to "do not make enough profit", we add more formality to the text as this sentence does not have any contractions and it has more elegant and precise words like "profit".