The sentence that has the correct parallel structure is the second option: Not only will I babysit, but I will also try to find a job at the mall. This is the only sentence that correctly uses the correlative conjunctions which is Not only..but also. The first sentence is incorrect because "and" is not paired with "not only", and the pair of "either" is "or".
The answer to your question is C.
It would be subject on the first one
