Your subscription contains several public IPv4 addresses (IP1, IP2, IP3, IP4, IP5). You plan to create a Standard SKU, public Azure Load Balancer named LB1 in West US. Which of the listed public IPv4 addresses can be assigned to LB1?

Standard SKU public Azure Load Balancers require Standard SKU public IP addresses. Basic SKU public IP addresses cannot be associated with a Standard SKU Load Balancer. IP3 is the only public IP address listed as a Standard SKU. Therefore, only IP3 can be assigned to LB1. The other IPs (IP1, IP2, IP4, IP5) are Basic SKU, which are incompatible with a Standard SKU Load Balancer.