Active compensation: refers to the behavior of an enterprise to actively make financial compensation to consumers for its defective products or services. Which of the following is active compensation? ['Xiao Wang and a few colleagues found a dead fly in the dish when spending money in a hot pot restaurant, so they went to the boss to discuss the situation. After more than half an hour of negotiation, the boss finally agreed to waive the order and apologize.', 'The canteen of a university received complaints from students about the low quality of meals and high prices, and immediately rectified. Three days later, the quality of meals in the canteen has improved significantly, and prices have also dropped.', 'A company found that a newly launched mobile phone exploded while charging, and soon publicly promised to the society: users can replace the mobile phone battery for free within 30 days, and the company will bear the cost of postage and travel expenses.', 'Lao Zhang bought a motorcycle last week and it feels good to ride. Two days ago, the manufacturer suddenly notified him to bring the original invoice to the designated repair shop to replace the circuit controller, and gave him a 200 yuan gas card.']