saturn, inc. paid $13,000 on accounts payable. how does this transaction affect the accounting equation of saturn?

In balancing the assets, liabilities, and networth, the equation would have to be,
            net worth = assets - liabilities

The equation signifies that the net worth is equal to the total asset subtracted with the total liabilities. 

If one is to pay of an accounts payable (which is a liability), one's liabilities will be subtracted. The asset used to pay the payable can be also be deducted. 

It would be option a