By default, all of them. They all act as a DNS proxy/forwarder on the local network and by default they get their DNS server settings via DHCP from the ISP. It is one of the first things I override when I get a new router.
And now, I don't even use the router for DNS, I use a Pi-Hole with DNS over TLS and DNSSEC to a trusted provider. My security gateway provides DoH and uses the Pi-Hole as its authority.