Given the guest speaker's presentation, which of the following statement$($s$)$ is$($are$)$ INCORRECT?

a$.$

The Millennium Development Goals $($MDGs$)$ build on the work begun by the $17$ Sustainable Development Goals $($SDG$)$s$.$

b$.$

Private financing works best when the activities that are financed are revenue$-$generating activities.

c$.$

The share of world population now living in low$-$income countries has decreased to less than $10\%.$

d$.$

Since the $1990$s$,$ the share of world population living in low$-$income countries has increased by $10\%.$

e$.$

Both A$)$ and D$)$ are incorrect.

f$.$

Both B$)$ and C$)$ are incorrect.