user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: when did roth ira originate? 
Knowledge Triplets: United States of America, location.country.administrative_divisions, Washington, D.C.
m.03pqvz1, people.place_lived.person, William V. Roth, Jr.
United States of America, location.country.first_level_divisions, Washington, D.C.
William V. Roth, Jr., book.author.works_written, The Power to Destroy
William V. Roth, Jr., book.author.works_written, Consequences of the Asian Financial Crisis
William V. Roth, Jr., people.person.education, m.02wmwpz
William V. Roth, Jr., people.person.religion, Episcopal Church
William V. Roth, Jr., common.topic.notable_types, U.S. Congressperson
William V. Roth, Jr., people.person.nationality, United States of America
William V. Roth, Jr., people.person.education, m.03lh3v4
United States of America, base.biblioness.bibs_topic.subsumes, United States of America
m.04d4y9r, government.government_position_held.jurisdiction_of_office, United States of America
William V. Roth, Jr., people.person.profession, Lawyer
William V. Roth, Jr., people.person.education, m.04yvvdd
William V. Roth, Jr., people.person.spouse_s, m.0j4l0tm
William V. Roth, Jr., book.author.works_written, Use of Seclusion and Restraints in Mental Hospitals
William V. Roth, Jr., government.politician.government_positions_held, m.0bfn2pw
William V. Roth, Jr., book.author.works_written, Complexity of the Individual Income Tax
William V. Roth, Jr., people.deceased_person.place_of_death, Washington, D.C.
United States of America, base.biblioness.bibs_topic.is_really, United States of America
William V. Roth, Jr., common.topic.notable_for, g.12554lq9j
William V. Roth, Jr., government.politician.government_positions_held, m.04d4y9r
William V. Roth, Jr., people.person.places_lived, m.03pqvz1
m.0bfn2pw, government.government_position_held.jurisdiction_of_office, United States of America
William V. Roth, Jr., book.author.works_written, International Tax Issues Relating to Globalization
William V. Roth, Jr., common.topic.image, William V. Roth, Jr
m.02wpr9m, education.education.student, William V. Roth, Jr.
m.0j4l0tm, people.marriage.spouse, William V. Roth, Jr.
Roth IRA, common.topic.article, m.023_lv
William V. Roth, Jr., military.military_person.participated_in_conflicts, World War II
Washington, D.C., base.biblioness.bibs_topic.subsumes, Washington, D.C.
William V. Roth, Jr., people.person.gender, Male
William V. Roth, Jr., people.person.place_of_birth, Great Falls
Washington, D.C., location.location.containedby, United States of America
Washington, D.C., base.aareas.schema.administrative_area.administrative_parent, United States of America
Washington, D.C., base.biblioness.bibs_topic.is_really, Washington, D.C.
United States of America, base.aareas.schema.administrative_area.administrative_children, Washington, D.C.
m.04d4y9r, government.government_position_held.office_holder, William V. Roth, Jr.
Washington, D.C., location.hud_county_place.place, Washington, D.C.
William V. Roth, Jr., book.author.works_written, Increasing Savings for Retirement
Roth IRA, symbols.namesake.named_after, William V. Roth, Jr.
William V. Roth, Jr., people.person.education, m.02wpr9m
William V. Roth, Jr., book.author.works_written, Irs Oversight
William V. Roth, Jr., common.topic.article, m.023xsh
William V. Roth, Jr., book.author.works_written, Irs Restructuring
William V. Roth, Jr., people.person.places_lived, m.04m13wk
Washington, D.C., location.administrative_division.country, United States of America
m.03pqvz1, people.place_lived.location, Great Falls
United States of America, location.country.capital, Washington, D.C.
m.0bfn2pw, government.government_position_held.office_holder, William V. Roth, Jr.
m.04yvvdd, education.education.student, William V. Roth, Jr.
Washington, D.C., base.biblioness.bibs_location.country, United States of America
Great Falls, location.location.people_born_here, William V. Roth, Jr.
m.04m13wk, people.place_lived.person, William V. Roth, Jr.
William V. Roth, Jr., government.politician.party, m.04d4y9x
m.02wmwpz, education.education.student, William V. Roth, Jr.
William V. Roth, Jr., symbols.name_source.namesakes, Roth IRA
Roth IRA, symbols.namesake.named_after, William V. Roth, Jr.
m.04d4y9x, government.political_party_tenure.politician, William V. Roth, Jr.
m.03lh3v4, education.education.student, William V. Roth, Jr.
Washington, D.C., location.administrative_division.first_level_division_of, United States of America
Great Falls, location.hud_county_place.place, Great Falls
William V. Roth, Jr., book.author.works_written, Medicare, Medicaid and S-Chip Adjustment Act of 1999
Great Falls, location.location.containedby, United States of America
William V. Roth, Jr., book.author.works_written, Retirement Security Policy

Answer: William V. Roth, Jr.