The wrong thing about the conditions for the formation of heavy rain is ()

According to China's meteorological regulations, heavy rainfall with a precipitation of more than 50 mm in 24 hours is called "rainstorm". According to its precipitation intensity, it is divided into three grades, that is, the 24-hour precipitation is 50 ~ 99.9 mm, which is called "rainstorm"; /kloc-rainstorm below 0/00 ~ 250 mm; More than 250 mm is called "rainstorm". The basic conditions for the formation of rainstorm are: continuous water vapor supply; There is a strong updraft, which leads to unstable atmospheric structure; The weather system that forms precipitation lasts for a long time (the weather systems that cause large-scale rainstorm mainly include fronts, cyclones, shear lines, eddies, troughs, typhoons and intertropical convergence zone, etc.). In addition, in arid and semi-arid areas, thermal thunderstorms can also cause short-term and small-scale heavy rains. So a, b and d are right, and c is wrong, which is an option that fits the meaning of the question.

Test site: the basic conditions for the formation of heavy rain

Comments: The difficulty of this question is general, which belongs to the basic question, and mainly examines students' basic cognitive ability to the conditions of rainstorm formation.