Final answer:
Sebastian must wait seven more years until he can run for Senate, as he has only been a naturalized U.S. citizen for two years and needs to meet the nine-year citizenship requirement.
Step-by-step explanation:
To answer the question, Sebastian must wait seven more years until he can run for the Senate. Although he is already 30 years old, which satisfies the age requirement, there is also a citizenship tenure requirement. According to the laws governing eligibility to serve as a U.S. Senator, a person must have been a U.S. citizen for at least nine years. Since Sebastian has been a naturalized citizen for only two years, he needs seven additional years to meet the nine-year citizenship requirement.