A scientist is studying the effects of sunlight on rose bushes. Which of the following is a testable question about this topic?

Does more sunlight make rose bushes grow taller?

Explanation:

When conducting a research, the researcher usually poses research questions in order to confirm or disprove the research hypothesis. A research question addresses the key issues and questions that the research project is intended to answer. Good research questions always aim at improving the body of knowledge on the selected topic of the research. Research questions must be narrowed down to specific details of the topic. They must also be testable, they must not be vague.

If I am studying the effect of sunlight on rose bushes, then the question, 'does more sunlight make rose bushes grow taller?' Is apt to the research because it can be tested by exposing various thorn bush plants to varying degrees of sunlight and recording my observation.

i believe the answer would be:

d. violin, clarinet, french horn, and tuba