Subnet1 in VNet1 uses the address range 10.20.10.0/24. Select the correct answer for each statement.

Why: In every Azure subnet the first four addresses and the last address are reserved: x.x.x.0 (network), x.x.x.1 (default gateway), x.x.x.2 and x.x.x.3 (Azure DNS mapping) and x.x.x.255 (broadcast). So the first address a VM can receive is 10.20.10.4, and a /24 offers 256 − 5 = 251 usable addresses. 10.20.10.1 is the gateway, 254 is the on-premises "minus network and broadcast" answer, and 250 subtracts one too many.