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".

[Q]: [header] How to install custom firmware [title] Record the router's model and version number. [step] These numbers are usually located near the manufacturer's logo, underneath or in back of the router. Write down the model and version information for future use. <sep> (A) [substeps] If you are using windows xp (default operating system), the model number can be found in the start menu under " system settings. " skip all the discussion menus, and then go to system preferences. (B) [title] Obtain the router's ip address and default gateway for your computer system. [substeps] Determine the ip address and default gateway for a pc. (C) [substeps] " w " with the green background is the serial number for the model. " p " with the red background means " unhappy operating system. (D) [substeps] It is easy to determine what operating system is running on your router if you don't know the model. Copy the model from the registry to convert it to your operating system.
[A]: B

[Q]: 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.
[A]: D

[Q]: [header] How to refinish bathtubs [title] Clean the entire surface of the bathtub with chemical cleaners to remove any soap scum and dirt residue. [step] The chemical cleaners will also help the bonding agent adhere to the surface. [title] Rinse and dry all surfaces thoroughly. <sep> (A) [title] Use a palm sander to gently roughen the surfaces you plan to refinish to make it easier for the paint to bond with the surface. [title] Tape paper or plastic over any surfaces you do not want to paint. (B) [title] Remove tub counter tops with an acrylic acid based cleaner with a small brush or the brush or spatula. [title] Remove mold, insects, and wax from the tub. (C) [step] Run a vapor bath if needed to remove soap scum or dirt residue from the bathtub. [title] Detach the tub frame by jacking the top part of it upwards and slamming it against the side and wall. (D) [title] Identify and avoid leaking faucets or shower heads, such as those with a drain. [title] Remove the line attaching a shower drain to the faucet.
[A]:
A