Option (a) and (b) represents electric field lines due to positive and negative charges. However, magnetic monopoles does not exist in nature. So, option (a) and (b) is not correct for magnetic field lines. Option (c) represents magnetic field lines for current carrying conductor. Also, electric field lines cannot form closed loop. So, option (c) is incorrect. Option (d) is possible for magnetic field lines of solenoid and electric field lines of dipole.Thus, option (d) is valid for both electric and magnetic field.