hi ajit257,
Well you can start the sentence with "that clause" , I sad that it is not preffered.
so, why D is wrong here.
first look at "
so poorly educated and trained" so needs a compliment "that" -for sexample "
so many young recruits to the United States work force are so poorly educated and trained
that"
- "so (adjective) that" - is correct usage
- "so .(adjective) why: -is wrong usage , please refer
MGMAT SC chapter 9 "idioms" for more details.
second.
the intended meaning is the following
some people are worried about smth and the dependent clause explains why they are worried.
Ask yourself about what word is the most useful to explain this WHY relationship?
informally, very often people use the construction "that's why" to explain cause-effect relationship.
Formally the word BECAUSE is used fot that.
In our sentence anw D uses wrong, or informal construction "That .....why" with a lot of words between them.
It is much better to use BECAUSE.
Read the sentence vice versa.
"many business executives fear this country will lose its economic preeminence (WHY?) BECAUSE many young recruits to the United States work force are [strike]so[/strike]poorly educated " and this is perfectly clear sentence.
Moreover, D starts with "That..." clause which is not the subject of the sentence.
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