ZJ Purchases Raw Materials on Credit from BD for £5,000

ZJ purchases raw materials on credit from BD for £5,000. However, when they arrive, half the raw materials turn out to be unsuitable so ZJ returns these goods to BD. Which one of the following is the correct double entry to record the £2,500 goods returned in ZJ's books of account?

A) Debit purchases £2,500, Credit trade payables £2,500
B) Debit purchases £2,500, Credit cash £2,500
C) Debit trade payables £2,500, Credit purchases £2,500
D) Debit cash £2,500, Credit purchases £2,500