As per RFC 1035 which transport layer protocol is used for DNS zone transfer?

HTTP is an Application Layer protocol used for web traffic and plays no role in DNS zone transfer operations.

RDP is a remote desktop application protocol unrelated to DNS or zone transfer mechanisms.

UDP is used for standard DNS queries and responses on port 53 but is explicitly not used for zone transfers due to its unreliable, size-limited nature.

Per RFC 1035, DNS zone transfers are performed over TCP port 53 because transferring an entire zone database involves large payloads that cannot reliably fit within UDP's 512-byte constraint. TCP's connection-oriented nature also guarantees that all resource records are delivered completely and in order from the primary to the secondary DNS server.