The planning horizon is defined as the amount of time the master schedule record or MRP record extends into the future. Which of the following is true about the planning horizon?

The length of the planning horizon is always fixed, regardless of how long or short production and supplier lead times may be$.$

There is no relationship between the length of the planning horizon and the lengths of production and supplier lead times.

In general, the longer the production and supplier lead times, the longer the planning horizon must be$.$

In general, the longer the production and supplier lead times, the shorter the planning horizon must be$.$