The mapping of an IPv4 multicast address to an Ethernet MAC address follows the standard defined in IETF RFC 1112. The Internet Assigned Numbers Authority (IANA) has allocated the MAC address prefix 01-00-5E for this purpose. The mapping procedure is as follows:

1. The first 24 bits of the MAC address are the fixed prefix 01-00-5E.

2. The 25th bit of the MAC address is always set to 0.

3. The remaining 23 bits of the MAC address are copied from the lower 23 bits of the 32-bit IPv4 multicast address.

For the IP address 239.33.42.107:

The lower 23 bits are derived from 33.42.107.

The second octet 33 (00100001) becomes 0x21 after masking the most significant bit (00100001 -> 0x21).

The third octet 42 is 0x2A.

The fourth octet 107 is 0x6B.

Combining these results in the MAC address 01-00-5E-21-2A-6B.

A. 01-00-5e-a1-2a-6b: The value a1 is incorrect. It would correspond to an IP second octet of 161 (10100001), not 33 (00100001).

C. 01-00-5e-21-2c-6c: The values 2c and 6c are incorrect hexadecimal conversions for the IP octets 42 and 107, respectively.

D. 00-01-5e-a1-2a-6b: The prefix 00-01-5E is incorrect. The IANA-specified prefix for IPv4 multicast is 01-00-5E.

E. 00-01-5e-21-2a-6b: The prefix 00-01-5E is incorrect. The standard prefix is 01-00-5E.

F. 00-01-5e-a1-2c-6b: This option has an incorrect prefix and incorrect hexadecimal values for the IP octets.

1. IETF RFC 1112, "Host Extensions for IP Multicasting": Section 6.4, "IP Multicast-Address to Ethernet-Address Mapping". This document specifies the standard mapping rule: "An IP host group address is mapped to an Ethernet multicast address by placing the low-order 23 bits of the IP address into the low-order 23 bits of the Ethernet multicast address 01-00-5E-00-00-00."

2. Nokia 7750 SR OS Services Guide, Release 19.10.R1: In the "IP Multicast" chapter, under the "Layer 2/3 Multicast Forwarding" section, the guide states: "The IANA owns an Ethernet MAC address block, 01:00:5e, for multicast... The 23 bits from the IP multicast address are mapped to the 23 variable bits of the MAC address." This confirms the mapping principle used in Nokia systems.

3. Kurose, J. F., & Ross, K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.): Chapter 4, Section 4.6.1, "The Internet's Network-Layer Forwarding Architecture". The textbook explains that for IP multicast, the low-order 23 bits of the IP multicast address are placed in the low-order 23 bits of a special range of Ethernet addresses starting with 01:00:5E.