In the cardinal utility analysis, the marginal utility of money is considered to be

Constant

The correct answer is Option (1) → Constant

Cardinal utility analysis assumes that the marginal utility of money remains constant. This assumption is crucial because money is used as the unit of measurement for utility (in terms of utils or money value). If the marginal utility of money were to change (e.g., decrease as a consumer's money stock increases), the measuring rod itself would be elastic and unreliable, making it impossible to accurately compare the marginal utilities of different goods.