Gross operating income is defined as:

Gross operating income (GOI) represents a critical metric in real estate analysis, particularly for investment properties. It is defined as revenue generated from all sources associated with the property, adjusted for expected losses such as vacancy rates and tenant credit issues. This definition is important because it provides a more accurate representation of the income that a property can reasonably be expected to generate over time.

This adjustment for vacancy and credit losses is vital because it reflects the reality that not all rental units will be occupied at all times and that some tenants may fall behind on their rent. By identifying GOI as revenue from all sources less these losses, it allows investors and property managers to gauge the effective potential income that can be relied upon, as opposed to merely stating the total gross revenue without consideration of these realities.

This focus on net revenue, rather than total revenue or cash flows without context, establishes a nuanced understanding of the property's financial performance, making Option B the correct definition of gross operating income.