Which statement correctly describes how MTU mismatches are addressed in the IS-IS neighbor-formation process? 

Answer options:

A. IS-IS checks the locally configured MTU against the MTU advertised in neighbor hello packets.
B. IS-IS checks the locally configured MTU against the MTU advertised in neighbor LSPs.
C. IS-IS does not check for MTU mismatches when forming a neighbor relationship.
D. IS-IS pads hellos, so neighbor relationships will not be formed on links with mismatched MTUs.

D