Which statement best distinguishes direct horizontal transmission from indirect horizontal transmission?

• A. Direct transmission always uses a living intermediary such as an insect to carry pathogens, whereas indirect transmission is strictly via inanimate objects and never involves airborne spread, which is always direct.
• B. Direct transmission involves immediate transfer from reservoir to host (e.g., handshake or sneeze onto someone), whereas indirect transmission involves an intermediary or significant delay (e.g., contaminated air, fomites, or vectors).
• C. Direct transmission means the pathogen replicates on surfaces before infecting a host, while indirect transmission implies the pathogen is immediately injected into the host at the time of contact with no intermediate; the two are distinguished by replication behavior.
• D. Direct transmission can only occur via large respiratory droplets and never via skin contact or mucous membrane exposure, while indirect transmission always requires ingestion and cannot infect respiratory mucosa directly without a vector.

Answer: (B)