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 draw curved surfaces in sketchup [title] Create a set of tangent arcs. [title] Click on the move icon and make a copy and move it a small distance away. [title] Connect them on each side. <sep> (A) [title] Go to the part about halfway between different arcs, and use the draw lines. [title] Draw a duplicate arc from below and make a copy of it. (B) [title] Take a lettered shape on each tangent. [title] Import these shapes and paste it on the jpg edge. (C) [title] Once the piece is finished, click on the pencil icon with some red on a of it. [title] If it's rotated, the two edges of the arc will be connected. (D) [title] Use the push/pull tool and pull it out to the width that you want it. [step] Hold down ctrl, click on the eraser tool and erase the lines that you see on the top and the bottom so the surface is' smooth'.

D