$\overline{C}$ in consumption function is not known as :

Slope of consumption

The correct answer is option (2) : Slope of consumption

A consumption function describes the relation between consumption and income. The simplest consumption function assumes that consumption changes at a constant rate as income changes. Of course, even if income is zero, some consumption still takes place. Since this level of consumption is independent of income, it is called autonomous consumption. We can describe this function as:

C = $\overline{C}$ + c.Y

The above equation is called the consumption function. Here C is the consumption expenditure by households. This consists of two components autonomous consumption and induced consumption ( c.Y ). Autonomous consumption is denoted by $\overline{C}$ and shows the consumption which is independent of income. If consumption takes place even when income is zero, it is because of autonomous consumption. The induced component of consumption, c.Y shows the dependence of consumption on income.

$\overline{C}$ is also known as intercept of the consumption function.

Slope of consumption is c and not $\overline{C}$.