问Today's low gasoline prices make consumers willing

HyeHye

Today's low gasoline prices make consumers willing to indulge their preference for larger
cars, which consume greater amounts of gasoline as fuel. So United States automakers are
unwilling to pursue the development of new fuel‐efficient technologies aggressively. The
particular reluctance of the United States automobile industry to do, so, however, could
threaten the industry's future.
Which of the following, if true, would provide the most support for the claim above about the
future of the United States automobile industry?
(A) A prototype fuel‐efficient vehicle, built five years ago, achieves a very high 81 miles per
gallon on the highway and 63 in the city, but its materials are relatively costly.
(B) Small cars sold by manufacturers in the United States are more fuel efficient now than
before the sudden jump in oil prices in 1973.
(C) Automakers elsewhere in the world have slowed the introduction of fuel‐efficient
technologies but have pressed ahead with research and development of them in preparation for
a predicted rise in world oil prices.
(D) There are many technological opportunities for reducing the waste of energy in cars and
light trucks through weight, aerodynamic drag, and braking friction.
(E) The promotion of mass transit over automobiles as an alternative mode of transportation
has encountered consumer resistance that is due in part to the failure of mass transit to
accommodate the wide dispersal of points of origin and destinations for trips.

请教E中, 介词短语 as an alternative mode of transportation 是用来修饰前面哪个名词(promotion, mass transit  还是 automobiles) ?