Barrier and different elevations question

[Badger]

If a barrier is placed on grounded terrain between two separte areas of elevated terrain will it block:

B
A B
B C
B

a) LOS between two characters each on elevated terrain on opposite sides of the barrier ??

b) LOS between two characters one on elevated terrain and the other on grounded terrain on opposite sides of the barrier ??

[Quebbster]

If a barrier is placed on grounded terrain between two separte areas of elevated terrain will it block:

B
A B
B C
B

a) LOS between two characters each on elevated terrain on opposite sides of the barrier ??

b) LOS between two characters one on elevated terrain and the other on grounded terrain on opposite sides of the barrier ??

a) No
b) yes
Barrier is no different than regular blocking terrain.