The most important objective of Network Planning and Management is: 

a. To maximize profitability for the airline, whether it is from flying more or flying less 

b. To provide good alternatives for its passengers in light of increasingly stiff competition 

c. To plan new routes for the airline's network to make full use of its aircraft fleet

d. To make effective use of its costly fixed assets which have to be paid regardless of how much (or little) they are used