Answer:
Option A Creating Product Differentiation
Step-by-step explanation:
The reason is that in the growth stage the company must add further features to the product to increase the product life and also capture the additional market share. This will only be possible if we have product differentiation.
The option D says that using anti-competitive strategy will give advantage to companies but this is not true, the reason is that the entrants enter the market when the product is at mature position (Normally). But this is not true in all situations.
So the best option is A