Given the task definition and input, reply with output. In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".

[header] How to keep files only online on dropbox on pc or mac [title] Find and click the dropbox icon in your notification area. [step] It looks like a tiny box next to the battery, wi-fi, and sound icons on your desktop. Clicking will open a pop-up window. <sep> (A) [substeps] On older versions of android and ios 10, this dialog box pops up when you open a new tab in your app store. For ios 10, this dialog box will appear the second time you open this window. (B) [substeps] On windows, your notification area is located in the lower-right corner of your taskbar at the bottom of your screen. On a mac, you can find it on your gray menu bar in the upper-right corner of your screen. (C) [substeps] Some users will enter a button to bring up the notification window, which contains the download tab, and just click on the installation tab to launch the install wizard. [title] Click the security box in the pop-up window. (D) [title] Go to " start wi-fi ". [step] The configuration menu will load when you click your mouse.
B