Answer: C. Future passive
Step-by-step explanation:
This is a passive form of future simple tense. In future tense, passive form consists of:
will + be + past participle (or third column). In this case, past participle of the verb 'to surprise' is 'surprised.'
Future passive differs from future perfect in that future perfect contains verb 'to have' instead of 'to be'. Future passive form of the verb 'to surprise' is 'will have surprised.' The correct answer is, therefore, C. Future passive.