Light utility trucks have become popular among consumers who buy them

LUTs are bought for their rugged appearance.
LUTs are are exempt from the government’s car-safety standards

Conclusion: If involved in a serious high-impact accident, a driver of one of these trucks is more likely to be injured than is a driver of a car that is subject to these government standards

Conclusion says that in case of an accident, a driver of an LUT is more likely to be injured than driver of a car.
It is assuming that the LUT does not meet the standard.
The conclusion is saying that out of 100 accidents of LUTs, 20 people will be injured.
But out of 100 accidents of cars, only 10 people (fewer than 20) will be injured.
The conclusion is not saying that fewer cars will be involved in accidents. It is saying that probability of the driver getting hurt in case the car is involved in the accident is lower. The discussion is on what happens when an LUT vs car gets involved in an accident. It is not on how many LUTs vs cars will get involved in accidents.

(A) the government has established safety standards for the construction of light utility trucks

The arguments tells us that LUTs are exempt from car safety standards. It doesn't tell us whether there are any LUT standards. If anything, it assumes that there are NO LUT standards.

(B) people who buy automobiles solely for their appearance are more likely than other people to drive recklessly

No. As discussed, the argument is all about what happens to people when they get in an accident. It is not about how likely they are to get into an accident.

(C) light utility trucks are more likely than other kinds of vehicles to be involved in accidents that result in injuries

As discussed, the argument is all about what happens to people when they get in an accident. It is not about how likely they are to get into an accident. This is irrelevant.

(D) the trucks’ rugged appearance is deceptive in that their engines are not especially powerful

How do powerful engines lead to safety, we don't know. Irrelevant.

(E) light utility trucks are less likely to meet the car-safety standards than are cars that are subject to the standards

Correct. It says LUTs are less likely to meet car safety standards because these standards are not forced on them. The argument does assume that just because the standards are not enforced, LUTs will not meet them and hence will be lacking in safety (lower safety than car). That is why drivers in LUTs are more likely to get injured when in an accident.

Answer (E)