The correct answer to the question is option 2: National Highways Authority. The National Highways Authority of India (NHAI) has recently launched two mobile apps named `MyFASTag` and `FASTag Partner`.
Option 1: Telecom Regulatory Authority is not the correct answer as it is not involved in the launch of these apps. The Telecom Regulatory Authority of India (TRAI) is responsible for regulating telecommunications and broadcasting in India.
Option 3: Airports Economic Regulatory Authority is also not the correct answer. This authority is responsible for regulating the economic aspects of airports in India.
Option 4: National Disaster Management Authority is not relevant to the launch of these mobile apps. This authority is responsible for disaster management in the country.
Therefore, the correct answer is option 2: National Highways Authority. The NHAI has launched the `MyFASTag` and `FASTag Partner` mobile apps, which are likely related to the implementation and management of the FASTag electronic toll collection system on national highways in India.