Over and over again he rehearsed it in wearisome until it had assumed a certain and almost invariable form. A)Expose.
B)Expenditure.
C)Repetition.
D)Option.

Over and over again he rehearsed it in wearisome repetition until it had assumed a certain and almost invariable form.

Hence the answer is :

answer: in october 1962, an american u-2 spy plane secretly photographed nuclear missile sites being built by the soviet union on the island of cuba. president kennedy did not want the soviet union and cuba to know that he had discovered the missiles. he met in secret with his advisors for several days to discuss the problem.

explanation:

keeping a cash reserve because cash flow is the the movement of money through a company and if it just sits there, it wont the movement