Use the table below to answer the following questions.

Table $11\mathrm{.}3\mathrm{.}1$

The following table shows the relationship between aggregate planned expenditure and real GDP in the hypothetical economy of Econoworld.

$\backslash$table$[[\backslash$table$[[$Real GDP$],[($billions of $2007],[$dollars$)]],\backslash$table$[[$Aggregate planned$],[$expenditure$]]],[0,100],[($billions of $2007$ dollars$),]]$

Refer to Table $11\mathrm{.}3\mathrm{.}1.$ Autonomous expenditure is

a$.$ $$100$ billion.

b$.$ $$50$ billion.

c$.$ $$500$ billion.

d$.$ zero.

e$.$ $$125$ billion.