Answer:
The correct answer is C. The verb in bold letters is in subjunctive mood.
Step-by-step explanation:
The subjunctive verb tense implies an eventual and hypothetical affirmation, on which a new affirmation will be made. It does not imply a conditional sentence, since there is no causal connection between both assumptions, but an affirmation that is not strictly firm but is based on a hypothesis or eventuality. Thus, in the presented sentence, the verb read is in the subjunctive, since it is essential that the person has read the manuscript to carry out a certain action in the future.