Answer:
Tiered brand
Explanation:
Tiered branding is a strategy used to leverage a company's reputation for a product line. This develops a distinct identity for the product line.
In the given scenario Sony brand I being leveraged to promote the Sony Walkman.
Usually the common tiered branding is two tiered branding. The top tier is the parent brand while the second tier is the sub brand.
So Walkman is the sub brand that uses the reputation of Sony to boost awareness and sales of the new product.