A group of students is investigating how the addition of salt impacts the floatation of an egg in water. Four identical cups were taken for the experiment. The data of the experiment are shown.Experimental RecordCupAmount of Water (mL)Amount of Salt (g)Level of Egg above Water14500Sinks to bottom2450682 cm34501363 cm44502724 cmWhich cup acts as a control group? 1 2 3 4