Answer: B.it is often impossible to identify with precision where a product is in the product life cycle.
Explanation:
It is very hard to identify for sure where a product is in the life cycle for a myriad of reasons chief amongst them being the lack of sufficient data, external factors influencing data and misalignment with historical data.
Products go through four stages in product life style starting from introduction, growth, maturity and decline and pinpointing exactly where a product is can be affected by the aforementioned factors.
For example, products like natural food or yoghurt might be considered declining then due to renewed interest for whatever reason, they are rejuvenated and go back into a Growth phase.
Or in another example, the data of a product may be based on a stable economic period which does not hold anymore so the sales of the product cannot be expected to be the same and thus it can be wrongfully recategorized.
If you need any clarification do react or comment.