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 reset your fitbit [title] Plug your charging cable into your computer. [step] Use the usb ports on your computer to plug your fitbit charging cable into your computer. [title] Plug your fitbit tracker into the charging cable. <sep> (A) [step] The fitbit tracker is a circular, gray thread on the top-right corner of your tracker. [title] Press and hold the " f8 " button. (B) [step] The charging cable is specifically designed to connect to your fitbit tracker. [title] Press and hold the button for 12 seconds. (C) [step] The charging cable is portable and can be plugged into a computer by attaching an adapter to the charging cable. [substeps] Connect your fitbit charger to your computer using its charging cable. (D) [step] The fitbit won't work for battery unless you have one, as it cannot charge the device, not including also your phone. [title] Power on your fitbit charger and turn on your device.
B