The argument was that poor people adopt certain practices that differ from middle class society in order to adapt and survive in difficult economic circumstance

answer; eliminate parking problems in cities, because a car took up only half as much space as a horse and buggy;

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.

the answer to your question is,

d. when a child was born.

-mabel < 3