The correct answer is D. As a result
Explanation:
A transition word or phrase always connects different elements and explains how these are related, due to this, the transition selected for a phrase should indicate accurately the relationship or link between the elements the transition connects. In the case presented the sentence "she was offered several scholarships" seems to be a consequence or result of "Christina worked diligently to make her grades in high school". According to this, it is necessary to have an effect or consequence transition such as therefore, so, consequently or as a result that is included in the options.
