Unlike
the body styles of the Boeing 747 and other Everett-built jets, ideal for long flights, the Boeing 737 has a cost-effective body style, consuming less fuel over medium-range distances.
Unlike requires Noun to Noun comparison. Looking at the non-underlined portion, we have Boeing 737 so we are comparing one boeing to other or to other jets.
A. the body styles of the Boeing 747 and other Everett-built jets,
This option suggests the comparison between body styles and Boeing 737. We require same or similar comparisons. Jets compared with body styles is not the correct comparison.
B. the body styles of the Boeing 747 and other Everett-built jets, which are
This option suggests the comparison between body styles and Boeing 737. We require same or similar comparisons. Jets compared with body styles is not the correct comparison.
C. the Boeing 747 and other Everett-built jets in having body styles
this option has distorted comparison. Unlike the jets in having body styles, the Boeing 737 . It compares jets in having body styles with Boeing. Comparison could have been Jets in having <non cost effective> body styles with Boeing that has cost effective body styles.
D. the Boeing 747 and other Everett-built jets, whose body styles are
Comparison is between Boeing/Jets with Jets ; over their body styles; looks fine. Whose can refer to plural form, that's good as well!
E. those of the Boeing 747 and other Everett-built jets with body styles
we have unclear reference for 'those' in this option, hence comparison elements cannot be clearly determined.
also it produces a run on sentence.
those of Boeign 747 and other Jets with body styles Boeing 737D looks good!