To increase its working capital, Babina Shoes Ltd has boldly printed "1/7, n/30" on all invoices. This means that for all accounts receivables,

a. a 1% cash discount may be taken if paid in 30 days; if no cash discount is taken, the full amount is due 7 days after the end of the month.

b. a 7% cash discount may be taken if paid in 1 day; if no cash discount is taken, the full amount is due 30 days after the invoice date.

c. a 1% cash discount may be taken if paid in 7 days; if no cash discount is taken, the full amount is due 30 days after the invoice date.

d. a 1% cash discount may be taken if paid in 23 days; if no cash discount is taken, the full amount is due in 30 days.