Xiaoming has to go to school outside the school every weekend. Xiaoqiang has never attended an English tuition class. As a result, Xiaoming and Xiaoqiang scored 95 and 55 respectively in the final exam. Therefore, Xiaoming's English score Xiaoqiang's reason is because of attending off-school cram school. Which of the following is true if it is the most difficult to weaken the above assertion:. ['Teachers in English tuition classes are not too serious.', 'Xiao Hong and Xiao Ming attended the English tuition class at the same time.', 'In the last English exam, Xiaoming and Xiaoqiang scored 99 and 39 respectively.', 'Xiaogang has not attended an English tuition class. He scored 80 points in English this time.']