A customer reports receiving a Significant Account Change $($SAC$)$ notification that their password had changed, but the customer didn't change the password. How should you respond?

a$.$ Verify the changed information with the customer

b$.$ Assure the customer that their information is safe and that they shouldn't worry

c$.$ Immediately inform

CPNI.Security@verizon.com

d$.$ Inform your Infosys manager