Good answer!
You just chose the right answer. The Eighteen Electron Rule is used correctly.
Cr = 6e
-
(
6
-C
6
H
6
) = 6e
-
3 x CO
T
= 6e
-
18e
-
Go to next problem
6-C6H6)
= 6e-
6-C6H6)
= 6e-