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 add potassium to an organic garden [title] Mix in muriate of potash or sulfate of potash. [step] Muriate of potash, or potassium chloride, and sulfate of potash, or potassium sulfate, are natural minerals. Muriate of potash tends to be cheaper, but the chlorine it contains can hurt the helpful microbes living in your garden's soil. <sep> (A) Gently mix these two together first, then add the zinc sulfate. [substeps] Zinc sulfate is readily available online, or in desalination solutions. (B) [substeps] You can substitute sodium thiamine (ipsin) or baking soda for sulfate because it is the most acidic fertilizer. Sodium thiamine is a common fertilizer in agricultural and organic gardens. (C) Sulfate of potash is safer, but it's a bit more expensive. [substeps] Check your product's label for specific instructions on how much to add per square foot or meter. (D) [substeps] There are many ways to add potassium to soil: you could use the most common method. You could sift the potassium into an empty feed colander and cool it before dropping it off.
C

A woman is playing a set of bagpipes in a room. she <sep> (A) begins to tap on the instruments, trying to play them in tune with each song. (B) laughs as a man helps her adjust the pipes, and continues to play. (C) goes back and forth, and she doesn't seem to be confident in her play. (D) strums them as she moves with the music.
B

[header] How to be a popular guy at a dance venue [title] Learn several dance steps. [step] There are many places to learn various dances. Dance studios teach dance classes for a fee. <sep> (A) One of the most commonly discussed steps in rehearsals is the following : [substeps] Crouching down on stage with one foot placed on the floor out in front of you on the opposite side of the dance floor. Lie on the floor on your back without your hair obscuring the floor. (B) Many dance venues offer a dance lesson before the dancing starts. The class is usually included in the admission cost for no additional charge. (C) [title] Determine if you want dancing in front of other people or dancing on a private dance floor. [step] Private dances do not need to be rented. (D) Ballroom dancing is a simple, individual dance. Ballroom is nothing but a combination of step styles.

B