The correct option is B. Before calling Dana, I'll make sure I know what I want to say.
The transition word used is "before" and it clearly states a chronological order. First, the person will make sure what he or she wants to say. And, then, he or she will call Dana.
Even though options A and D have transition words, "therefore" is used to express the result of something and "however" is used to express contrast. Option C, on the other hand, does not have any transition word.
The correct answer is B. Before calling Dana, I'll make sure I know what I want to say.
Explanation:
Transitions are words included within a sentence or between them to show the relationship between the elements linked, this relationship can be of many types including cause and effect, contrast or chronological order relationship. In the case of chronological relationship this includes words such as before, after, then, next, soon or later that are related to time and therefore express the order events occur.
According to this, the sentence that uses a transition of this type is "Before calling Dana, I'll make sure I know what I want to say" because the word "before" is a transition that indicates chronological relationship; also this has been used correctly because "I'll make sure I know what I want to say" occurs before "calling Dana".
