A

This question tests your understanding of the question

"A light promise will lead to a low faith" means that promises that are easily obtained always lack credibility and are often misunderstood. If things seem too simple, they must be very difficult to implement; people who make promises to others easily will not keep their promises. We can know from this that making promises easily will inevitably lack trustworthiness. Not making promises easily is an important guarantee for keeping one's word. We should be cautious when making promises in cooperation. Therefore, items 1, 2 and 3 are correct, and 4. Try not to make promises in cooperation. This statement is wrong. According to Lao Tzu It emphasizes not to make promises easily in cooperation, so item ④ is wrong, so item A is correct.