To complete the sentence: "Purpose, timeliness, precise content and pre-thinking are among the qualities of effective business \_."

The question asks to complete the sentence: "Purpose, timeliness, precise content and pre-thinking are among the qualities of effective business _____."

These qualities directly relate to how information is conveyed and received within a business setting.

• Purpose ensures the message has a clear objective.
• Timeliness ensures the message is delivered when it is most relevant.
• Precise content ensures the message is accurate and clear.
• Pre-thinking involves planning the message before it is sent.

All these elements are crucial for successful communication.

The correct option is b.

$$\boxed{\text{b. Communication}}$$