Answer:
Step-by-step explanation:
1) C. A and B are not shifts and D specifically says the changes are unnecessary.
2) D. A and B are both positive things and C is simply wrong.
3) D. A, B, and C put the topic of the sentence before what the topic does. These are all active voice. Passive voice puts the action before the action-doer like in D.
4) 90% sure this is D for the reasons I stated in 3.