How many Dell EMC SC9000 slots, per controller, are available for PCle cards?

How many Dell EMC SC9000 slots, per controller, are available for PCle cards?
A . 3 full height and 3 half-height card slots
B . 3 full height and 4 half-height card slots
C . 3 full height (one reserved for write cache) and 3 half-height card slots
D . 4 full height (one reserved for write cache) and 3 half-height card slots

Answer: D