Explanation:

Let’s break this down:

- Option 1: Usage of machines. This sounds logical, but in practice, usage can be tough to track accurately. Insurance is about potential replacement or repair costs, not wear and tear.

- Option 2: Floor area. That’s more relevant for property or fire insurance. The size of a room doesn’t reflect machine value or insurance risk.

- Option 3: Value of machines. This is the go-to standard. Insurance costs should reflect the value of the assets—you pay more to insure something that’s worth more, simple as that. It’s fair, direct, and what insurance companies use when they set premiums for equipment.

- Option 4: Number of workers. The number of workers affects liability or accident insurance, not machinery coverage. Workers don’t change the replacement cost of machines.

So, your chosen option—Option 3—is spot on.