Is the passage of dialogue written correctly or incorrectly?

"Why won't the cat eat?" Tom said worriedly.
"She could be sick," Mom replied.
"I was afraid of that," Tom said. "She hasn't been herself for a few days," he added.
"I'll call the veterinarian," promised Mom.

A.
correctly

B.
incorrectly

Question

Is the passage of dialogue written correctly or incorrectly? 

    "Why won't the cat eat?" Tom said worriedly. 
    "She could be sick," Mom replied. 
    "I was afraid of that," Tom said. "She hasn't been herself for a few days," he added. 
    "I'll call the veterinarian," promised Mom.
 
 A.
correctly
 
 B.
incorrectly

anonymous · Answer

B, after why wont the cat eat needs to be a comma