Final answer:
The fuel-oil from the oil storage tank likely contains both dirt and sediment due to the complex nature of petroleum oil and the process of sedimentation during storage and handling.
Step-by-step explanation:
The fuel-oil coming from the oil storage tank can contain both dirt and sediment. This mixture is due to the fact that petroleum oil, which fuel oil is derived from, is a complex mixture of organic compounds including alkanes, cycloalkanes, alkenes, and aromatic hydrocarbons. These compounds vary depending on their source, and during storage and handling, various impurities such as dirt and sediment can enter the fuel oil.
As oil is stored in tanks, sediments which are denser materials can settle at the bottom, while lighter components can rise to the top. Sedimentation tank processes also show that materials such as grease and oil, when involved with wastewater, tend to float while the heavier sediment settles to the bottom. Therefore, when considering the contents of fuel-oil from a storage tank, it's reasonable to expect that both dirt and sediment might be present, making option 3 ('Both Dirt and Sediment') the correct answer.