vessel of 4 $$m^{3}$$ contains oil which weighs 30 kN. The specific weight of the oil is

A

4.5 $$\frac{K N}{m^{3}}$$

B

6 $$\frac{K N}{m^{3}}$$

C

7.5 $$\frac{K N}{m^{3}}$$

D

10 $$\frac{K N}{m^{3}}$$