All of the following statements about parents' choice of childcare arrangements for infants and toddlers are accurate except

a. mothers who work evening or nighttime shifts are more likely than mothers who work daytime hours to use care by family members
b. mothers with higher incomes are more likely than other mothers to be successful in achieving a match between their preferred and actual childcare arrangements
c. the cost of nonparental care for infants tends to be lower than the cost nonparental care for children over the age of two
d. low-income families tend to spend a higher percentage of their income on childcare expenses than higher income families spend

C