You will be given a definition of a task first, then some input of the task.
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 build antennas [title] Choose the rod length for your antenna. [step] You will need 2 rods that are 46.4 inches (117. 8 cm) long if you are designing the antenna to listen to non-commercial radio stations such as college channels. [substeps] You will need 2 rods that are 42.4 inches (107.5 cm) long if the antenna is for listening to fm band stations. <sep> (A) [title] Understand your antenna's shade profile. [step] The pin at the bottom of the antenna should give the antenna a fixed shade profile. (B) [title] Choose 6-12 rods for the antenna or pole too. [step] Once you have decided which rods you would like to use and they are securely arranged the rods should rise above the ears of the antenna. (C) Two rods that are 27.4 inches (55. 84 cm) wide each will work well if you have two antenna lengths to choose from. (D) [title] Place your rods perpendicular to each other and tie them together with a piece of string or tape. [step] You might need to tape together extra pieces to brace the frame.
Output:
D