Concept:Manufacturers sell directly to consumers when middlemen are not useful or cannot handle the product properly.
Explanation:Goods made to a customer's specification need direct contact between the manufacturer and the buyer.
Perishable goods must reach consumers quickly, so avoiding intermediaries helps reduce delay.
Highly technical goods require expert installation, guidance, or after-sales service, which the manufacturer can best provide.
Advertising by the manufacturer does not itself make direct selling necessary.
Widely demanded goods are normally distributed through wholesalers and retailers to reach a larger market.
Therefore, the situations that justify direct selling are i, iii, and iv.
Answer:A. i, iii and iv only