Answer:
All A, B, C, D are functions/goals of signs on a store's exterior yet the main goal is to enabling the customer to identify the business at a glance.
Step-by-step explanation:
Signs are a vital tool of communication and have been like since the ancient past.
In this question, the signs in store are meant for the customers to identify the business.
Apart from that, signs also enable store's to diversify and be unique from their competitive stores/businesses.
and you know what? Signs can be trade marked as well! When this happens, only the original user can display the sign and none other can do it! I f any one does that, legal actions can be taken against them!