Which two DNS records are specifically designated for Lync Online?

You are configuring Microsoft Lync Online for a private high school. You are creating the DNS
settings on the school’s public DNS server.
Which two DNS records are specifically designated for Lync Online? Choose two.

A.
CNAME autodiscover

B.
SRV_sip

C.
CNAME lyncdiscover

D.
TXT SPF

Explanation:
There is two SRV records and two CNAME record that you need to create.
* lyncdiscover Type: CNAME
* sip Type: CNAME
* _sipfederationtls Type: SRV
* _sip._tls Type: SRV
DNS Records required to use Lync Online (Office 365) with a Vanity Domain
https://www.martinhatch.com/2012/02/dns-records-required-to-use-lync-online.html