A(hypothetical) benevolent social planner whose goal is to allocate resources with the greatest efficiency should:

Maximizing total surplus is the aim of a (hypothetical) benevolent social planner whose goal is to allocate resources with the greatest efficiency.

To add, a social planner is a decision-maker who attempts to achieve the best result for all parties involved.

depends.

explanation:

giant impact theory - the moon was formed from the collision between earth and another mars-sized body.

colliding planetesimals hypothesis - the moon was formed from the same cloud of material as earth.

capture hypothesis - the moon was locked into orbit by earths gravity as it was passing by it.

accretion hypothesis - the moon was formed from collisions and combining of planetesimals.

i think this is right, if not and you know better let me know.