Final answer:
A salary check received at 6pm on 12/31, after all banks have closed, constitutes constructive receipt in the current year ended December 31.
Step-by-step explanation:
Constructive receipt is an accounting concept that determines when income is considered received for tax purposes.
Out of the given options, a. A salary check received at 6pm on 12/31, after all banks have closed, would constitute constructive receipt in the current year ended December 31.
This is because the check was received before the end of the year, even though it couldn't be deposited until the next business day due to bank closures.