OFFICIAL EXPLANATION
Creating a successful marketing campaign can not only multiply sales by four times but also attract potential investors.A. not only multiply sales by four times but also attract
This answer choice is stylistically flawed. Four times is redundant as the same meaning can be expressed in fewer words. Look for a more concise answer choice.
What helps us identify this question as a Redundancy question as well as identify this mistake is the following Stop Sign: (multiplied) one/two/three/four timesB. quadruple sales but also attract
Although this answer choice replaces the redundant phrase multiply by four times with quadruple, it misuses the structure not only X but also Y, creating a Parallelism error. But also must be preceded by not only.
What helps us identify this question as a Parallelism question as well as identify the mistake is the following Stop Sign: not only... but also...C. not only quadruple sales but also an attraction to
Although this answer choice corrects the original Redundancy error by changing by four times to quadruple, it is still grammatically incorrect. The same part of speech that follows not only must also follow but also. Here, not only is followed by the verb quadruple. But also, however, is followed by the noun attraction.
What helps us identify this question as a Parallelism question as well as identify the mistake is the following Stop Sign: not only... but also...D. not only quadruple sales but also attract
The phrase multiply by four times is redundant as the same meaning can be expressed in fewer words. This answer choice uses the more concise quadruple.E. not only quadruple sales by four times but also attract
Although this answer choice replaces the redundant phrase multiply by four times with quadruple, it is still redundant. Since the verb quadruple means multiply by four times, there is no need to use the words by four times. This creates redundancy.