alwaysudit
This question is from the GMAT prep question pack 1 and here is what the official answer to why "B" is wrong
" The final Clause in the sentence That went into service does not provide a verb to complete the subordinate clause that begins with the words since the first jet transports
can this problem be rectified if we delete "that" from [/i]since the first jet transports that went[/i] .In this case will when serve as the verb of the subordinate clause
Where is
when used? Also,
when is not a verb. If you remove
that, the subordinate clause in B would be exactly the same as the the subordinate clause in the correct option C (and it would be correct).
However, this issue (The final Clause in the sentence
That went into service does not provide a verb to complete the subordinate clause that begins with the words
since the first jet transports) is actually very subtle.
Perhaps easier way to eliminate B is the incorrect usage of "present continuous" ("are reading") and the subject-verb disagreement ("has").