33. Which of the following statements about PCR is incorrect? (A) Quantitative PCR can directly quantify the relative concentration of mRNA. (B) The use of 95°C during the reaction process is to cause DNA denaturation. (C) The temperature setting for the annealing step will affect the specificity of the product. (D) The use of 72°C during the reaction process is for polymerization, and the time must be adjusted based on the product size. (E) The discovery of Taq DNA polymerase, which can withstand high temperatures, is the key to PCR technology.