The best option for determining whether the increase in availability is worth the investment for a single year of usage is to calculate the value of improved availability to be $900, and determine that the increase in availability is not worth the investment. To calculate the value of improved availability, we can use the following formula:

Value of improved availability = Revenue * (New availability - Current availability)

Plugging in the given numbers, we get:

Value of improved availability = $1,000,000 * (0.9999 - 0.999) = $900

Since the value of improved availability is less than the investment of $2,000, we can conclude that the increase in availability is not worth the investment.