Petra will soon complete her doctoral degree in psychology. she, like the highest percentage of doctoral level psychologists, will work

She will work as a therapist.

Explanation:

A therapist or psychotherapist refers to a professional in terms of mental health who helps clients to have a better life-style, develop some important  cognitive and emotional skills, as well as manage some challenges.

A therapist also helps other people to find their strengths and in this way, they could confront the different emotions, as well as the different situations. Thus, people can learn and thrive in their lives.  

answer would be b, a tariffs main purpose is to protect domestic production and jobs.