Step 1: Evaluate the sentence structure.
- "To be a great manager" sets up the main subject, requiring a series of qualities to follow.
- The phrase "requires strong inter-personal skills" fits grammatically and maintains parallelism in listing the qualities.
- The list should maintain parallel structure, using and to connect the qualities.
Step 2: Eliminate the incorrect options.
- (A) is incorrect because "and demands" breaks the parallelism.
- (C) changes the meaning by suggesting the manager demands the ability to think fast.
- (D) starts with a gerund "requiring," making the sentence ungrammatical.
- (E) introduces "but with," which is unnecessary and incorrect here.
Therefore: The correct answer is \boxed{(B)}.