Which security classification do you apply when the unauthorized disclosure of a sop contents could resonably be expected to cause damage to national security?

Secret.

Answers:

TOP SECRET is: You will apply a TOP SECRET classification to an SOP in which the unauthorized disclosure of its contents could reasonably be expected to cause exceptionally grave damage to the nation's national security. (GRAVE being operative Word)

SECRET is: You will apply a SECRET classification to an SOP in which the unauthorized disclosure of its contents could reasonably be expected to cause serious damage to national security. (SERIOUS being the operative Word)

CONFIDENTIAL is: You will apply a CONFIDENTIAL classification to an SOP in which the unauthorized disclosure of its contents could reasonably be expected to cause damage to national security. (no modifier of the amount of damage)