There has been an increase ___ sales after the company hired new workers.a) withb) onc) ind) of

To determine the correct preposition to fill in the blank, let's analyze the sentence step by step:

1. Identify the context of the sentence:

   • The sentence talks about an increase in something as a result of hiring new workers.

2. Understand the relationship between the words:

   • The word "increase" is often followed by a preposition that indicates what is increasing.

3. Evaluate each option:

   • a) "with" - This preposition suggests accompaniment or association, but it doesn't fit well with "increase" in this context.
   • b) "on" - This preposition is used to indicate a surface or a specific day, and it doesn't fit well with "increase" in this context.
   • c) "in" - This preposition is commonly used to indicate inclusion within a space, time, or condition, and it fits well with "increase" when talking about an increase in a specific area or aspect.
   • d) "of" - This preposition is used to indicate belonging or a part of something, but it doesn't fit well with "increase" in this context.

4. Choose the most appropriate preposition:

   • The correct preposition that fits the context of the sentence is "in."

Therefore, the correct sentence is: "There has been an increase in sales after the company hired new workers."