1) D. 4; this is because you can conduct experiments to see if larger-petaled sunflowers really do attract more bees than smaller-petaled sunflowers.
2) A. The exact experiment can be repeated by others and the results compared.; they will get a more accurate conclusion to which sweetener will attract a larger number of ants once they compare results after doing the exact same experiment.
3) A. All types of metal are attracted to magnets.; we know this is the answer because that's the only reason she got DIFFERENT types of metal. If she was testing if HEAVIER metal objects are more attracted, than why wouldn't she get the same type of metal but get different types of weight?