how to reduce hydrogen sulfide hazard in residual fuel oils?

 how to reduce hydrogen sulfide hazard in residual fuel oils?

1) ventilation to lower the concentration of vapour in the ullage space and in specific areas where vapours may accumulate should be carried out as soon as practicable 
2) keep heating the oil to maintain a higher temperature 
3) transfer the oil to some other tank using a fuel transfer pump

Ans____1) ventilation to lower the concentration of vapour in the ullage space and in specific areas where vapours may accumulate should be carried out as soon as practicable