GMAT Prep SC - spraying of pesticides

[khojason]

The spraying of pesticides can be carefully planned, but accidents, weather conditions that could not be foreseen, and pilot errors often cause much larger deposits of spray than they had anticipated.

A. weather conditions that could not be foreseen, and pilot errors often cause much larger deposits of spray than they had
B. weather conditions that cannot be foreseen, and pilot errors often cause much larger deposits of spray than
C. unforeseeable weather conditions, and pilot errors are the cause of much larger deposits of spray than they had
D. weather conditions that are not foreseeable, and pilot errors often cause much larger deposits of spray than
E. unforeseeable weather conditions, and pilot errors often cause much larger deposits of spray than they had

[spoiler]Ans: B[/spoiler]



May I know why "they had anticipated" in Option A is incorrect? Is it because we do not know what "they" is referring to?

May I also ask if "unforseeable weather conditions" is preferrable than "weather conditions that could not be foreseen"?

[ankurmit]

Ya you are right..

'They' dont have any antecedent in A,C and E

now we are left with B and D.

B seems better option

[niksworth]

It is true that pronoun they does not have a referent in A, C and E.

B and D are the possibly correct answer choices.

@ankurmit
I am not sure if a case of parallelism makes B the right choice (spraying of pesticides and weather conditions are not in parallel. Rather, accidents, weather conditions and pilot errors are in parallel and this does not necessitate the modifier to take up the form that cannot be foreseen)

I wonder why is weather conditions that cannot be foreseen preferable over weather conditions that are not foreseeable.

Expert may please help out.

[ankurmit]

You are right dear..I have modified post..

Both are parallel but D seems me somewhat clumsy..better experts comment on this quistion