Looking at the answers:

'Allow airlines to better compute navigation and route charges' --> INCORRECT. Knowledge of the aircraft's mass and CG position allows for performance planning in the vertical, rather than horizontal.

'Allow selection of the real, optimum cruising flight level' --> CORRECT. This will depend on the aircraft's weight, CG position & air temperature and will vary as fuel is burnt.

'Are only required for take-off and landing, to comply with load sheet requirements' --> INCORRECT. Knowledge of the mass and CG of the aircraft are essential in flight for a number of reasons, including selection of optimum flight levels, diversion planning, fuel management (think A380 moving fuel from the tail tank in flight to control the CG position) etc.

'Are unimportant since all performance decisions are based on expected masses on the operational flight plan'--> INCORRECT. Expected masses are used for planning only. In flight, any operational decision will be based on actual conditions.