Which option is part of designing a set of experimental procedures? A. Conducting the experiment
B. Developing a question about a phenomenon
O O O
C. Looking for errors in the collected data
D. Identifying the controlled, manipulated, and responding variables

**urgent** roberto plans to use two transformers to reduce a voltage of 120 v to 4 v. he uses a transformer that has 300 coils in the primary winding and 50 coils in the secondary winding. he has four other transformers, as listed in the table. which transformer should roberto use to have an ending voltage of 4 v? a- w b-xc- yd- z