Correct option is C
Given:
People: Alice, Bob, Carol, David, Emily, Frank.
Key Information:
· David sits between Alice and Emily.
· Carol sits to the immediate right of Bob.
· Frank and Alice are not neighbors.
· Carol is an immediate neighbor of Frank
From the given information following diagram can be drawn-

From the above diagram David sits to the immediate right of Emily.
Thus, the correct answer is (c) David.