Place where bankers exchange cheques and adjust balances

Answer: Option B

One word substitute is Clearing house.

Exchequer: a royal or national treasury.
Clearing house: a bankers' establishment where cheques and bills from member banks are exchanged, so that only the balances need be paid in cash.
Bank: the land alongside or sloping down to a river or lake.
Commerce: the activity of buying and selling, especially on a large scale.