Pick your answer from: 1. a year 2. not enough information 3. a decade 4. a second

SEOUL Arms control experts estimate that the dismantlement of North Korea's nuclear program could take a decade to complete, and cost $20 billion, if a nuclear agreement is reached between U.S. President Donald Trump and North Korean leader Kim Jong Un when they meet in Singapore on June 12. "The hard work has not yet begun, and it is gong to take sustained energy on the part of the United States, South Korea, Japan, China and North Korea. It's going to be a multiyear long process," said Daryl Kimball, the executive director of the Arms Control Association in Washington. President Trump has said he expects a "very positive result" from the North Korea nuclear summit, but he also said it will likely be the beginning of a process to resolve differences over the extent of the North's denuclearization, and the specifics regarding what sanctions relief, economic aid and security guarantees would be offered in return. U.S. Defense Secretary Jim Mattis said on Sunday that North Korea would only receive sanctions relief after it takes "verifiable and irreversible steps to denuclearization." This position aligns closer to the Kim government's stance that denuclearization measures and concessions be matched action for action. And it backs away from demands made by some in the president's national security team that Pyongyang quickly and unilaterally dismantle all its weapons of mass destruction before any concessions would be offered. North Korea is estimated to have 20 to 80 nuclear warheads, both known and covert nuclear research and processing sites, and thousands of ballistic missiles that can be launched from mobile vehicles, and submarine based launchers have been tested in recent years. With such an extensive nuclear arsenal it could cost $20 billion to achieve the U.S. goal of complete, irreversible, and verifiable nuclear dismantlement (CVID), according to a recent study conducted by Kwon Hyuk-chul, a Kookmin University professor of security strategy. Kwon based his assessment in part on past nuclear deals... According to the above context, answer the following question. The denuclearization process will probably take
Answer:
1.