Step 1: Understand the limitations of planning.
Planning has some limitations, such as rigidity, wastage of time, and high costs. However, the "basis of control" is not typically considered a limitation.
Step 2: Evaluate the options.
- Rigidity in planning refers to being inflexible and unable to adapt to change.
- Wastage of time can occur if the planning process is too lengthy or inefficient.
- Huge cost may be incurred due to extensive research or investment required for planning.
- The basis of control is a necessary aspect of planning and is not a limitation.
Step 3: Conclude.
The correct answer is (C) as the basis of control is integral to the planning process, not a limitation.
Final Answer:
\[
\boxed{\text{Basis of control}}
\]