$8\mathrm{.}4$ How does a product idea differ from a product concept and a product image? Where do these concepts fit in the new product development process? $($AACSB: Written and Oral Communication$)$

$8\mathrm{.}5$ Name and explain the five stages in the product life cycle $($PLC$).$ What message does the product life cycle hold for marketers? $($AACSB: Written and Oral Communication$)$