SCENARIO: Developers of a new housing scheme spend money putting in roads, lighting and clearing land surrounding the scheme.

(5) The private benefit curve is

a. shifts outwards to the social benefit curve

b.shifts inwards to the social benefit curve

c. remains unchanged

(6) The private cost curve is

a. shifts outwards to the social cost curve

b.shifts inwards to the social cost curve

c. remains unchanged

(7) The Efficient output is found where the ______the socially efficient quantity.

a. social cost and social benefit curve intersect

b. private cost and social benefit curve intersect

c. private cost and private benefit curve intersect

d. social cost and private benefit curve intersect

Please give explanation