When a positively charged sphere is brought near a metallic sphere, it is observed that a force of attraction exists between the two. It means

Suppose a positively charged sphere is brought near an uncharged metallic sphere, then on nearer surface of the uncharged sphere, negative charge is induced and on farther surface, positive charge is induced. Hence, a force of attraction will be observed between these two spheres. Therefore, if a force of attraction is observed between a positively charged sphere and a metallic sphere, it cannot be concluded that the metallic sphere is necessarily negatively charged. Therefore, option (2) is wrong and options (1) and (4) are correct.