The Attorney General could only ascend to the presidency if .
Congress allowed it
the President allowed it
Constitution was cahnged
those above him/her couldn't serve

those above him/her couldn't serve

Explanation:

Attorney General is seventh in the line, so it is unlikely that something like this can happen. Still, in the case it happens it will happen only when those above him are not able to perform their duty. Of course this never happened in history.

answer; ///the correct answer is,by introducing a merit system of nobility.

- three-quarters or two-thirds..

- "the constitution provides that an amendment may be proposed either by the congress with a two-thirds majority vote in both the house of representatives and the senate or by a constitutional convention called for by two-thirds of the state legislatures."

< 3