Step 1: Understand what the publisher needs:
The publisher wants readers to send back their reviews.
The readers should not pay any postage. The publisher will bear the cost.
Step 2: Recall the right service:
A Business Reply Envelope is a pre-addressed envelope sent by a business to its customers.
The business has a licence and pays the postage when the reply arrives.
The customer just drops it in a letter box.
Step 3: Check the other options:
Speed Post is a fast delivery service, and the sender pays. It does not help the readers.
Registered Post gives proof of posting and delivery, but the sender pays more and the readers still pay for their replies.
VPP (Value Payable Post) is used to collect the price of goods from the receiver, which adds a cost for the buyer.
Final Answer:
The best choice is the Business Reply Envelope, which is option (C).