The average stock is?

The following information relates to Mallam Amidu Kachella for the year ended on 31/12/2005.

Opening stock = #4,000
Purchases = #16,000
Sales = #30,000
Debtors = #6,500
Creditors = #4,200
Cash in hand = #800
Closing stock = #5,600
Bank overdraft = #3,000

A. #1,600
B. #4,800
C. #5,600
D. #9,600

Correct Answer: Option B

B. #4,800