At which phase of the DHCP process will a DHCP server provide the client with an IP address, subnet mask, and default gateway?

DHCP Server works under DORA process

D for Discover. The host machine will Broadcast discover packet in the network.

O for offer. Dhcp server listens this in port 68 and offer the ip, subnet mask, default gateway and dns in 67 port.

R for request. After receiving the offer packet the host machine request the server to assign those configuration.

A for Acknowledgement. The server respond back by sending ack packet to the host by conforming that everything is assigned as per request.