Which RIR is responsible for IP address assignments in Canada and the US?

The correct answer is ARIN, which stands for the American Registry for Internet Numbers. ARIN is specifically responsible for the allocation and management of IP address resources in Canada, the United States, and several territories in the Caribbean.

ARIN plays a crucial role in ensuring that the distribution of IP addresses is done in a fair and organized manner, which is essential for maintaining the stability of the internet infrastructure in these regions. It provides critical services such as the registration of IP address allocations, maintaining the public WHOIS database, and facilitating the exchange of information between network operators.

The other organizations mentioned in the options operate in different regions: APNIC covers the Asia-Pacific region, AFRINIC serves Africa, and LACNIC is responsible for Latin America and the Caribbean. Each of these Regional Internet Registries (RIRs) is designated to manage IP address allocation within its respective geographic domain, emphasizing the role of ARIN specifically for North America.