Answer:
d. new entrants will have to spend heavily to overcome existing customer loyalties.
Explanation:
When the product is different and can be recognized by an incumbent so the same should be acted as the entry barrier as the new entrants should spend more amount so that they would able to overcome the loyalties of the customer that are pre-existed in the market
So according to the given situation, the option d is correct
And, the remaining of the options should be incorrect