You may choose a standardized tool because a your required to use it b such tools are fail-proof. c such tools capture spontaneous, child-directed learning. d. such tools often capture learning in all of the domains.

the answer should be b

the plates spread at mid-ocean ridges (they are divergent plate boundaries) which allows magma to rise through the weakness between the plates. the magma then emerges as lava from the boundary and cools, creating a new crust.