the writer already used this phrase choose another phrase to convey the same idea “tantalizing treat”

B)There are several qualities I look for in a friend. Most important, I like someone who participates in the same extra-curricular activities. Second, I want someone who will not share my secrets.  

Explanation:

In the above options provided, the best answer will be  

B) There are several qualities I look for in a friend. Most important, I like someone who participates in the same extra-curricular activities. Second, I want someone who will not share my secrets.  

For, in this sentence, we are talking about the qualities one wants in a friend. Option (A) is wrong as it uses "instead" in the adjoining sentence. "Instead" is used when we want something in place of the other.

Option (C) uses "although", which is a conjunction that is used when introducing the statement. Here, it is used at the end of the sentence.

Option (D), the use of 'for example' in the sentence have no meaning to it. There is no connection with the previous sentence that it follows. And, also it is not an example of the 'extra-curricular activities' it is talking about.