If b is the mean proportionate of a and c then find the value of $$ {(a-b)^{3}:(b-c)^{3}}$$ ?

• A. $$ {a^{3}:b^{3}}$$
• B. $$ {a^{2}:b^{2}}$$
• C. $$ {b^{2}:c^{2}}$$
• D. $$ {a^{3}:c^{3}}$$