Answer:
The correct answer is A. real-time PCR can measure the amount of DNA amplified as the reaction proceeds, while standard PCR cannot.
Explanation:
PCR (Polymerase Chain Reaction) is a molecular biology technique. Conventional PCR and real-time PCR are diferent types of PCR, and are both used to exponentially amplify DNA molecules. In both types, a polimerase enzyme is employed to sinthesize DNA copies. The main difference is that conventional PCR is qualitative whereas real-time PCR is quantitative. So, real-time PCR permits not only to detect and amplify DNA but also permits to perform a quantification of the target DNA. This is accomplished by measuring a fluorescence signal - which is directly the amount of DNA amplified- during the course of the reaction.