Why is the Declared ID sync failing to working properly?

A client notifies an architect that Declared ID sync is not working when a site visitor authenticates. The architect first checks the AAM Data Source to make sure it is set up properly.

– ID: 543213

– Integration Code: cust_id

– ID Type: Cross Device

– ID Definition: Person

– Data Source Settings (Inbound): Customer ID

After checking the debugging tool, the architect sees the below data points returned upon authenticating on site.

d_cid_ic: 2991c7a7-6fc74f-431jc12

d_jsonv: 1

d_ld_ts=1142144713051

d_mid: 16184299510823404650127548759430712925

Why is the Declared ID sync failing to working properly?
A . The Data Source ID Type should be Cookie and not Cross-Device.
B . The d_jsonv parameter should return a “0” value.
C . The Experience Cloud ID is not enabled.
D . The d_cid_ic parameter is missing the integration code.