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 make cookies and cream rice krispie treats [title] Melt the butter in a large saucepan. [step] Over a low heat setting, melt the butter to where it is nearly all liquid. [title] Add the marshmallows. <sep> (A) [step] Before the butter melts completely, stir it occasionally with a wooden spoon. ( the butter needs to melt evenly before you can add it. (B) [step] When the butter has melted, add the marshmallows. [title] Saute on low for 20 minutes or until the marshmallows have dissolved. (C) [step] Combine and stir the butter and marshmallows until everything is melted thoroughly. [title] Remove the pan from the heat and add the 10 oreos that were chopped. (D) [step] Pour the melted butter into the saucepan with the marshmallows. Stir the mixture in until the marshmallows are completely melted.
C