The correct answer is option 3. Both options (1) and (2).
Fats and oils can block drains.
Since they harden the soil in sewage pipes and clog them, oils and fats shouldn't be flushed down drains. Fats obstruct drains by becoming lodged in the soil's pore spaces. It prevents the water from flowing. Additionally, in an open drain, lipids prevent soil from absorbing water by obstructing the soil's porosity. Oils and fats shouldn't be flushed down the toilet for this reason. | 
