How do the three types of operations decisions relate to one another in practice?

1. Planning, control, and improvement are described as three stages, which makes them sound strictly sequential. 2. In practice all three decisions are ongoing rather than one-off. 3. They may also occur simultaneously, so a firm can be planning a new facility while controlling the one it already runs. 4. Improvement work in particular never ends, because more efficient methods keep appearing. 5. Option B mistakes a description of stages for a rule about order. 6. Option D is wrong because every producing firm faces all three, whether it makes goods or delivers services. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 10 "Achieving World-Class Operations Management", section 10.1 Production and Operations Management_