The table below summarizes the results of an experiment using a group of normal cells and three other cell lines of the same type of cells that each carry a different mutation in a membrane receptor protein. The receptor is part of a signal transduction pathway that is stimulated by glucose-6-phosphate. Cells were tested for their ability to respond, via the signal transduction pathway, to a variety of ligand molecule, as shown in the table Based on these data, which statement about these three mutations is plausible? Percent cellular response via signal transduction pathway Ligand Normal (nonmutant) Mutant 1 Mutant 2 Mutant 3 Glucose-6- phosphate Glucose Galactose Mannose 100 100 95 97 94 89 95 Mutation 3 has no effect on ligand binding, while mutations 1 and 2 have dramatic effects on ligand binding Mutations 1 and 3 have no effect on ligand binding, while mutation 2 has a dramatic effect on ligand binding Mutations 1 and 3 broaden the specificity of ligand binding, while mutation 2 eliminates ligand binding Mutation 1 broadens the specificity of ligand binding, while mutations 2 and 3 eliminate ligand binding Mutations 1, 2, and 3 each broaden the specificity of ligand binding in different ways