Final answer:
The optional step in the accounting cycle is An end-of-period spreadsheet is prepared.
Step-by-step explanation:
The optional step in the accounting cycle is C. An end-of-period spreadsheet is prepared. This step involves summarizing all the transactions and adjusting entries in a spreadsheet to calculate the final financial results for the period. The purpose of this spreadsheet is to provide an overview of the company's financial performance, but it is not a required step in the accounting cycle.