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". 

Ex Input:
[header] How to change trackpad settings on macbook pro [title] Find the system preferences. [step] Starting from your main desktop screen there are two ways to find the system preferences where the mouse and touchpad settings will be located : [title] Bring your cursor to the bottom screen and find the system preferences application. [step] The icon looks like a box with three gears inside it. <sep> (A) Open that to find all your system preferences. [substeps] Alternatively, you can use the spotlight feature. (B) On macbook pro this icon resembles a round blue square with a horizontal green dot on it. On other applications this icon is actually a box with a gear, and is small in appearance. (C) It can be located on the taskbar or in the upper left-hand corner of the window. [title] Let the system preferences application perform its work. (D) [title] Click the customize key in the dialog box. [title] Follow the on-screen instructions to change the customization function.

Ex Output:
A


Ex Input:
The boy watches his mom vacuum as he jumps on the bed. The boy then lays down on the bed as he sees his mother finish the job. then the boy <sep> (A) shows his stomach as she vacuums the bed. (B) plays the accordion and pans the camera to his dad playing the accorion. (C) plays with some toys and walk down a street as he looks at a lot of houses. (D) gets off the bed and jumps down to the ground to look under the bedside table.

Ex Output:
D


Ex Input:
The water sounds still play and the man shows you various moves and what they mean under water. the logo <sep> (A) and the tightening dial appears at the bottom of the screen. (B) rewinds and the man gives pointers on how to properly play. (C) appears on the screen and the man continues to demonstrate how the trick is done and back to the camera roll. (D) then reappears on the screen and the video ends.

Ex Output:

D