Mark the letter A, B, C, or D to indicate the underlined part needs co

Mark the letter A, B, C, or D to indicate the underlined part needs correction in each of the following questions.

 

The New York City subway system is the most longest underground railroad operating in the world.
 

• A. A. subway system
• B. B. most longest
• C. C. most longest
• D. D. railroad