Select the option that is related to the third number in the same way as the second number is related to the first number:

15 : 350 :: 12 : ?

208

a  :  a² + (\(\frac{a}{3}\))³ 

⇒ 15  :  (15)² + (\(\frac{15}{3}\))³ 

⇒ 15  :  (15)² + (5)³ = 225 + 125 = 350

⇒ 15  :  350

Similarly,

⇒ 12  :  (12)² + (\(\frac{12}{3}\))³ 

⇒ 12  :  (12)² + (4)³ = 244 + 64 = 208

⇒ 12  :  208