There is a sentence that is missing in the paragraph below. Look at the paragraph and decide in which blank (option 1, 2, 3, or 4) the following sentence would best fit.

Sentence: This has meant a lot of uncertainty around what a wide-scale return to office might look like in practice.

Paragraph: Bringing workers back to their desks has been a rocky road for employers and employees alike. The evolution of the pandemic has meant that best-laid plans have often not materialised. _ (1) _ The flow of workers back into offices has been more of a trickle than a steady stream. _ (2) _Yet while plenty of companies are still working through their new policies, some employees across the globe are now back at their desks, whether on a full-time or hybrid basis. _ (3) _ That means we're beginning to get some clarity on what return-to-office means - what's working, as well as what has yet to be settled. _ (4) _