Sulphide ion is soft base and its ores are common for metals.\( (a) \) Pb \( \quad (b) \) Al \( \quad (c) \) Ag \( \quad (d) \) MgChoose the correct answer from the options given below:
(a) and (b) only
(a) and (d) only
(c) and (d) only
(a) and (c) only