Which One of the Following Is an Example of a "Flexibility

Which one of the following is an example of a "flexibility" option?

A) a company has an option to close down an operation if it turns out to be unprofitable.
B) a company agrees to pay more to build a plant in order to be able to change the plant's inputs and/or outputs at a later date if conditions change.
C) a company invests in a project today to gain knowledge that may enable it to expand into different markets at a later date.
D) a company invests in a jet aircraft so that its ceo, who must travel frequently, can arrive for distant meetings feeling less tired than if he had to fly commercial.
E) a company has an option to invest in a project today or to wait a year.