Medium term planning is

The correct answer is C. 2 to 5 years.

Medium-term planning is a type of planning that covers a period of 2 to 5 years. It is used to set goals and objectives for the organization and to develop strategies to achieve those goals. Medium-term planning is important because it allows the organization to make sure that it is on track to achieve its long-term goals.

Option A, 6 months, is too short a period for medium-term planning. Option B, 1 year, is the shortest possible period for medium-term planning. Option D, 5 to 15 years, is too long a period for medium-term planning.