New threat intelligence primarily impacts the frequency component of risk calculations.
CRISC states:
"When new information about threats is available, it must be incorporated into risk assessment by adjusting threat event frequencies in related scenarios."
* A and D are statistical manipulations, not practical first steps.
* C addresses impact, not likelihood.
Hence, B. Revise the threat frequency is correct.
CRISC Reference: Domain 2 - IT Risk Assessment, Topic: Incorporating Threat Intelligence.