I think it’s NO CHANGE. All of the other ones doesn’t make sense.
Research is a scientific investigation which follows a procedure of observing, hypothesizing, testing, analysing and presenting the data.Variables are contained in every research because they serve as the objects to be observed or the result of those observationsWe appreciate your questions. Please, never hesitate to ask more in Brainly your queries.
heres the picture of the answers :)