单项选择题

International airlines have rediscovered the business travelers, the man or woman who regularly jets from country to country as part of the job. This does not necessarily mean that airlines ever abandoned their business travelers. Indeed, companies like Lufthansa and Swissair would rightly argue that they have always catered best for the executive class passengers. But many lines could be accused of concentrating too heavily recently on attracting passengers by volume, often at the expense of regular travelers. Too often, they have seemed geared for quantity rather than quality.
Operating a major airline in the 1980s is essentially a matter of finding the right mix of passengers. The airlines need to fill up the back end of their wide-bodied jets with low fare passengers, without forgetting that the front end should be filled with people who pay substantially more for their tickets.
It is no coincidence that the two major airline bankruptcies in 1982 were among the companies specializing in cheap flights. But low fares require consistently full aircraft to make flights economically viable, and in the recent recession the volume of traffic has not grown. Equally the large number of airlines jostling for the available passengers has created a huge excess of capacity. The net result of excess capacity and cut-throat competition driving down fares has bean to push some airlines into collapse and leave many others hovering on the brink. What does "in-flight service" (Line 1, Para, 5) mean
[A] Service on the plane. [C] Flights within one country.
[B] A new safety device. [D] Charge-free air service.