NetBIOS name resolution is correct because UDP port 137 is assigned to the NetBIOS Name Service that Windows file servers use for name registration and name queries.

UDP port 137 carries the NetBIOS Name Service traffic which lets Windows hosts map NetBIOS names to IP addresses on local networks. Blocking UDP 137 will therefore interfere with NetBIOS name resolution and can break legacy Windows name lookups, browsing lists, and some older file sharing workflows that rely on NetBIOS.

NetBIOS name resolution is considered a legacy feature and modern Active Directory environments and newer Windows configurations typically prefer DNS and direct SMB over TCP port 445. This makes NetBIOS less common on hardened networks and newer exam items may emphasize DNS and SMB over NetBIOS.

HTTPS is incorrect because HTTPS runs over TCP port 443 with TLS and is unrelated to UDP port 137.

SMTP is incorrect because SMTP is an email transfer protocol that uses TCP ports such as 25, 587, or 465 and it does not use UDP 137.

DNS is incorrect because DNS primarily uses UDP port 53 for standard queries and TCP port 53 for zone transfers and larger responses. DNS name resolution is separate from the NetBIOS name service on UDP 137.

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