Which of the following pairs of statements is true in terms of configuring MD authentication?

A.
Interface statements (OSPF, EIGRP) must be configured; use of key chain in OSPF

B.
Router process (OSPF, EIGRP) must be configured; key chain in EIGRP

C.
Router process or interface statement for OSPF must be configured; key chain in EIGRP

D.
Router process (only for OSPF) must be configured; key chain in OSPF

Explanation:
BD
This is an exact question from the Cisco Official Certification Guide 210-260.
Source: Cisco Official Certification Guide, Table 13-1 “Do I Know This Already?” Section-to-Question Mapping,
p.343
SOURCE: http://www.ciscopress.com/store/ccna-security-210-260-official-cert-guide-9781587205668 (Update
TAB > Download the errata ) < this is updates for cert guide
The correct answer changed from “Router process (only for OSPF) must be configured; key chain in EIGRP” to”Router process or interface statement for OSPF must be configured; key chain in EIGRP”