question: What is modulation format recognition in optical networks? option 1: The process of estimating the Quality of Transmission (QoT) for a new lightpath option 2: The process of determining the cause of network failures option 3: The process of identifying the specific modulation format used in the transmission option 4: The process of optimizing the launch power of optical amplifiers option 5: The process of controlling the post-amplifier power discrepancy between different lightpaths 