Considering grammar, spelling, and punctuation as well as ease of understanding, which sentence is most acceptable?

The selected sentence is the most acceptable because it employs proper grammar, spelling, and punctuation while ensuring clarity and ease of understanding. The use of "employees" correctly reflects the plural form, making it clear that multiple individuals are being referenced, which is suitable in a workplace context. The phrase "reporting to work" is also correctly structured, indicating that the focus is on those individuals in the act of going to work.

Moreover, "must enter the time on their time card" maintains correct grammatical agreement, with "their" appropriately used to refer to the plural subject "employees." This is essential for clarity and ensures that the sentence is easily understood by the reader.

Other options present issues such as the singular "employee" in a context suggesting multiple workers, incorrect use of "there" instead of "their," and the use of an apostrophe in the incorrect context. These mistakes can lead to confusion and impact the overall readability of the sentence. Thus, the chosen sentence stands out as the clearest and most grammatically sound option.