Effective Estate Planning Tool for Tax Reduction

Michael is a 60-year-old individual with two adult children, Emily and James. He has recently started to consider estate planning to ensure that his assets are distributed according to his wishes after his passing. Michael is particularly concerned about minimizing estate taxes and ensuring a smooth transfer of assets to his children. He is considering various estate planning tools and strategies.

Which of the following options is likely the most effective tool for Michael to reduce estate taxes while ensuring the transfer of wealth to his children?