I want to know the answer to the following question:
Who helped North Korea prepare for war by surveying the country?
All the background I'm provided with is that "After conferring with Mao that this would be MacArthur's most likely strategy, Zhou briefed Soviet and North Korean advisers of Lei's findings, and issued orders to Chinese army commanders deployed on the Korean border to prepare for American naval activity in the Korea Strait.". Is that enough to answer the question?