$2$a: The displacement current also guarantees that Maxwell$$s Equations conserve charge.

Imagine that you have a solid conducting sphere of radius R which is initially neutral. You

place a large quantity of positive charge at the center of the sphere. This produces a radially

outward current which varies with time. Eventually, all the charge will be on the outside of

the sphere and the current will be zero. Use this charge conservation equation in Ampere$$s Law and verify that the two terms on the

right hand side of Ampere$$s Law do cancel each other in this case