Answer:
b)Horizontal diversification
Step-by-step explanation:
Horizontal diversification is defined as the process by which a business starts providing a product that is unrelated to its previous products supplied.
However the market is a similar one.
In the given scenario Marble Cakes, Inc. has set up business in three other states with additional menu options of cupcakes, donuts, and coffees to generate new customers.
The new set of products are completely different from the one initially supplied, but sales is in similar market as before.