At December 31, Tremble Music had account balances in Accounts Receivable of $300,000 and in Allowance for Uncollectible Accounts of $1,000 (credit) before any adjustments. An analysis of Tremble's December 31 accounts receivable suggests that 5% of the account balances are not expected to be collected. The balance of Allowance for Uncollectible Accounts after adjustment will be:

$15,000.

Explanation:

So, in this particular question we are given the following parameters or data or information which is going aid us in solving the problem;

=> "At December 31, Tremble Music had account balances in Accounts Receivable of $300,000 "

=>" At December 31, Tremble Music had account balances in Allowance for Uncollectible Accounts of $1,000 (credit) before any adjustments"

=> "An analysis of Tremble's December 31 accounts receivable suggests that 5% of the account balances are not expected to be collected"

So, looking at the third point from the question above, we see that "accounts receivable suggests that 5% of the account balances", thus, we have that;

$300,000, which is the account receivable multiply by 5%. That is;

$300,000 × 5/100 = $15,000.

c is the correct answer.