At 20 $\degree$ C an Aluminum Ring Has an Inner Diameter of 5

At 20 $\degree$ C an aluminum ring has an inner diameter of 5.000 cm, and a brass rod has a diameter of 5.020 cm. Keeping the brass rod at 20°C, which of the following temperatures of the ring will allow the ring to just slip over the brass rod? ( $\alpha$ _Al = 2.4 *10 ^{- 5} / $\degree$ C, $\alpha$ _brass = 1.9 *10 ^{- 5}/ $\degree$ C )

A) 111 $\degree$ C
B) 187 $\degree$ C
C) 228 $\degree$ C
D) 437 $\degree$ C