Teacher: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".
Teacher: Now, understand the problem? Solve this instance: [header] How to buy a tanzanite online [title] Know the basics : [step] The four c's, as in diamonds, is applicable to tanzanites as well. These are: color, clarity, cut and carat. Unlike in diamonds, color in tanzanites is the most significant feature. <sep> (A) Use the image below to research how tanzanite works. [title] Most of the single ingredients in tanzanite will come in the glycolic acid diacetyl, an acid which is responsible for the lightening chemical called xalox calfenne. (B) [substeps] Carat: the cut is distinctive and measured by a' diamond' saw. Carat: the stone sits in a flawless tone (preventing cracking). (C) The blue in a tanzanite is valued in terms of hue, tone and saturation. Clear, deep blue violet tanzanites are valued more than dusky ones. (D) [title] Register online : [step] Just like with jewelry, you will be required to register for online exchange on the tanzanite website. You can register online in either amazon or itunes.
Student:
C