Step 1: Understand the concept of planning.
Planning is a crucial management function that involves setting goals, defining objectives, and determining the best course of action to achieve desired outcomes.
Step 2: Evaluate the options.
- Planning is goal-oriented as it sets clear objectives.
- It is objective-oriented because planning helps achieve organizational targets.
- Planning also involves mental processes of analyzing and decision-making.
Step 3: Conclude.
All these characteristics apply to planning, making option (D) the correct answer.
Final Answer:
\[
\boxed{\text{All of these}}
\]