Analysis of the Sentence
1. Identify the relationship: The word "Notwithstanding" (meaning in spite of or although) establishes a contrast between the senator's behavior in her personal life and her behavior in her public role.
2. Analyze the contrast:
- Public Role: She "always spoke directly and candidly" (honest, straightforward).
- Personal Life: She had a tendency to ________ when journalists' questions "blatantly pried."

3. Determine the required meaning: To contrast with "spoke directly and candidly," the blank must mean the opposite: to avoid being direct, to speak indirectly, or to become guarded/defensive when discussing her personal life.

Evaluating the Options
We are looking for synonyms meaning "to speak evasively" or "to become hostile/defensive in response to prying."
- A. cower: To crouch down in fear. (Implies too much fear.)
- B. bristle: To react angrily or defensively. (Fits the reaction to "blatantly pried" questions, but lacks a good synonym in the list.)
- C. speak evasively: To respond indirectly or vaguely, especially to avoid an issue. (Direct opposite of "spoke directly and candidly." Strong Fit)
- D. vacillate: To be indecisive or waver. (Irrelevant to the nature of the answer.)
- E. prevaricate: To speak or act in an evasive way; to avoid telling the truth by not addressing the question directly. (Strong Fit; a direct synonym for "speak evasively.")
- F. elaborate: To add more detail. (The opposite of the required evasive behavior.)

The best pair of synonyms that captures the idea of avoiding directness in speech is speak evasively and prevaricate.

The correct answers are C. speak evasively and E. prevaricate.