Selected Answer: BC Chromatic dispersion is not an advantage; it's a challenge that has to be overcome https://www.cisco.com/c/dam/global/de_at/assets/docs/dwdm.pdf

Selected Answer: BC Two advantages of using Dense Wavelength Division Multiplexing (DWDM) over traditional optical networks are: Increased Capacity: DWDM lets multiple optical signals be multiplexed onto a single fiber, which raises the capacity of an optical network. This makes it possible to send a large amount of data over long distances without needing extra physical fibers. Improved Reliability: DWDM offers a more resilient and reliable network by allowing multiple optical signals at different wavelengths to travel over a single fiber. If there is a fiber cut or another failure, the network can reroute traffic over a different wavelength, reducing downtime and disruptions.

C & E. Topology Flexibility One recent core network trend is the consolidation of multiple Layer 2 and Layer 3 networks into a single IP/Multiprotocol Label Switching (IP/MPLS) infrastructure. Even with this Layer 2 and 3 convergence, the underlying transport layer (Layer 1) of many service provider core networks has continued to use SONET/SDH. Some network inefficiencies result from how core transport networks are built out to support the IP or service layer over the SONET/SDH layer, supported by an underlying DWDM infrastructure. Protection Options A recovery time of less than 50 ms can be achieved mapping Ethernet directly over DWDM. https://www.launch3telecom.com/shared_media/datasheet/product_data_sheet09186a00801849e7.pdf

Selected Answer: BC as per the cisco docs

Selected Answer: BC Should be B, C

A& C. Topology Flexibility One recent core network trend is the consolidation of several Layer 2 and Layer 3 networks into one IP/Multiprotocol Label Switching (IP/MPLS) infrastructure. Even with this Layer 2 and 3 convergence, the underlying transport layer (Layer 1) of many service provider core networks has continued to rely on SONET/SDH. Some network inefficiencies come from the way core transport networks are built to support the IP or service layer over the SONET/SDH layer, backed by an underlying DWDM infrastructure. Protection Options A recovery time of under 50 ms can be achieved by mapping Ethernet directly over DWDM. https://www.launch3telecom.com/shared_media/datasheet/product_data_sheet09186a00801849e7.pdf

BC is correct