What is periodically multicasted (every 10 seconds) by the DIS on a LAN to ensure IS-IS Link State Database accuracy?

What is periodically multicasted (every 10 seconds) by the DIS on a LAN to ensure IS-IS Link
State Database accuracy?

A.
IIH

B.
LSP

C.
CSNP

D.
ISH

E.
PSNP