Consider the following statements and selsct the correct ones :
a. Iron ans steel industries developed around lake Michigan in USA due to availability of good quality coal.
b. Pittsburg - Youngstown area is the leading producer of steel in USA.
c. The Lorraine area in France is significant for steel production
d. The south Manchurian region accounts for nearly 60% of China's pig-iron production.
Select the correct answer from the given alternatives .