The correct answer is B, "Pre-cleaning, leak testing, and manual cleaning," as these processes are essential for endoscope reprocessing. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, proper reprocessing of endoscopes is critical to prevent healthcare-associated infections (HAIs), given their complex design and susceptibility to microbial contamination. The initial steps of pre-cleaning (removing gross debris at the point of use), leak testing (ensuring the endoscope’s integrity to prevent fluid ingress), and manual cleaning (using enzymatic detergents to remove organic material) are foundational to the reprocessing cycle. These steps prepare the endoscope for high-level disinfection or sterilization by reducing bioburden and preventing damage, as outlined in standards such as AAMI ST91 (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.3 - Ensure safe reprocessing of medical equipment). Failure at this stage can compromise subsequent disinfection, making it a non-negotiable component of the process.

Option A (intermediate level disinfection and contact time) is an important step but insufficient alone, as intermediate-level disinfection does not achieve the high-level disinfection required for semi-critical devices like endoscopes, which must eliminate all microorganisms except high levels of bacterial spores. Option C (inspection using a borescope and horizontal storage) includes valuable quality control (inspection) and storage practices, but these occur later in the process and are not essential initial steps; vertical storage is often preferred to prevent damage. Option D (leak testing, manual cleaning, and low level disinfection) includes two essential steps (leak testing and manual cleaning) but is inadequate because low-level disinfection does not meet the standard for endoscopes, which require high-level disinfection or sterilization.

The emphasis on pre-cleaning, leak testing, and manual cleaning aligns with CBIC’s focus on adhering to evidence-based reprocessing protocols to ensure patient safety and prevent HAIs (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.4 - Implement environmental cleaning and disinfection protocols). These steps are mandated by guidelines to mitigate risks associated with endoscope use in healthcare settings.