A bottle that is completely full of cooking oil has a mass of $1.30\,\text{kg}$. After exactly half of the oil has been used, the mass of the bottle together with the oil left inside is $0.90\,\text{kg}$. What is the mass of the empty bottle?
- A$0.40\,\text{kg}$
- B$0.50\,\text{kg}$
- C$0.65\,\text{kg}$
- D$0.80\,\text{kg}$