As shown in the figure, it is the temperature and pressure change chart of 18 ~ 2 1 month measured by a weather station in China. Look at the picture and answer questions 39 ~ 40. The weather system p

As shown in the figure, it is the temperature and pressure change chart of 18 ~ 2 1 month measured by a weather station in China. Look at the picture and answer questions 39 ~ 40. The weather system passing through here is ( A, according to the picture in the middle and late period, the temperature has been falling and the air pressure has been rising, so it is correct to judge that it is a cold front;

B, according to the picture, the temperature has been falling and the air pressure has been rising, so it is judged to be a cold front, so it does not meet the meaning of the question;

C, according to the picture, the temperature has been falling and the air pressure has been rising, so it is judged to be a cold front, so it does not meet the meaning of the question;

D, according to the picture, the temperature has been falling and the air pressure has been rising, so it is judged as a cold front, which does not meet the meaning of the question.

So choose: a.