a. Revenue recognition is the determination of the point and the amount at which income is accounted for b. Income should not be accounted for unless inflow of economic benefit is probable and the amount thereof may be estimated reliably. c. Income should not be accounted for unless it is received in cash d. A sale made subject to the customer right to return within a week should not be recognized as income until that week is over Which of the above statement are correct and Why, please explain in brief