Step 1: Understanding the Concept:
This question requires an understanding of time-related prepositions within the context of the Present Perfect Continuous tense ("has been working").
In English grammar, prepositions like "since" and "for" indicate the duration of an action, but they are used in very specific, non-interchangeable ways.
Step 2: Detailed Explanation:
The sentence structure "Subject + has been + V-ing" indicates an action that commenced in the past and continues into the present moment.
To complete this sentence, we must decide between a point in time or a duration of time:
1. "Since" (Correct): This preposition is used to mark the starting point of an action. It is followed by a specific time, date, year, or event. Since "2022" is a specific calendar year marking the exact moment the work began, "since" is the only grammatically appropriate choice.
2. "For": This preposition is used to describe a period of time or a total duration. We use "for" when counting the units of time (e.g., for three years, for five months). If the sentence said "three years" instead of "2022", then "for" would be correct.
3. "From": While "from" can show a start time, it is typically paired with "to" or "until" (e.g., from 9 AM to 5 PM). In the Present Perfect Continuous tense, "since" is preferred over "from" to show ongoing continuity from a past date.
4. "By": This indicates a deadline or a point in time by which an action will be finished (e.g., I will finish by 2026). It does not fit a continuous ongoing action.
Because 2022 is a fixed point on the timeline, we must use "since" to link it to the ongoing action.
Step 3: Final Answer:
The correct preposition to fill the blank is option (B).