单选题：请阅读Passage，完成第小题。 Polyester (聚酯) is now being used for bottl

请阅读Passage，完成第小题。
Polyester (聚酯) is now being used for bottles． ICI, the chemicals and plastics company,believes that it is now beginning to break the grip of glass on the bottle business and thus take advantage of this huge market.
All the plastics manufacturers have been experiencing hard times as their traditional products have been doing badly world-wide for the last few years．Between 1982 and 1984 the Plastics Division of ICI had lost a hundred and twenty million dollars, and they felt that the most hopeful new market was in packaging, bottles and cans.
Since 1982 it has opened three new factories producing "Melinar", the raw material frown which high quality polyester bottles are made.
The polyester bottle was born in the 1970s, when soft drinks companies like Coca Cola started selling their drinks in giant two-liter containers．Because of the build-up of the pressure of gas in these large containers, glass was unsuitable．Nor was PVC, the plastic which had been used for bottles since the 1960s, suitable for drinks with gas in them．A new plastic had to be made.
Glass is still cheaper for the smaller bottles and will continue to be so, unless oil and plastic become much cheaper, but plastic does well for the larger sizes.
Polyester bottles are virtually unbreakable．The manufacturers claim they are also lighter, less noisy when being handled, and can be reused． Shopkeepers and other business people are unlikely to object to a change from glass to polyester, since these bottles mean few breakages, which are costly and time-consuming．The public, though, have been more difficult to persuade． ICI's commercial department is developing different bottles with interesting shapes, to try and make
them visually more attractive to the public.
The next step could be to develop a plastic which could replace tins for food．The problem here is the high temperatures necessary for cooking the food in the container.
Why is ICI's Plastics Division interested in polyester for bottles? A．The other things they make are not selling well.
B．Glass manufacturers cannot make enough new bottles.
C．They have factories which could be adapted to make it.
D．The price of oil keeps changing.