The correct option is B more negative
Electron gain enthalpy depends on two factors:
(i) Atomic size
(ii) Nuclear charge
Smaller atomic size means a stronger nuclear pull on the electrons. Thus, the energy required to add an extra electron will be less.
Chlorine is a smaller atom when compared to sulphur and it requires very less amount of energy to add an extra electron. So, it has more negative electron gain enthalpy than sulphur.