High-level managers deal with long-term planning, whereas low-level managers plan for the short term. However, this does not necessarily mean that middle-level managers do not deal with long- or short-term planning, or low-level managers do not deal with medium-term planning. In fact, they do. Even though the time horizons for long-term and short-term might change from one sector to the other and from one company to the other, for most business organizations long-term planning has a time horizon that is more than 3 years, whereas short-term planning is done for a period less than a year. For medium-term planning, which is dealt with by the middle management, it is more than a year- 3 years. The correct answer is Choice E.