The correct IPv6 address notation follows the format of eight groups of four hexadecimal digits, separated by colons. The address must have exactly eight groups unless it uses the double colon (::) to represent consecutive groups of zero value. The double colon can only appear once in an address to avoid ambiguity.
Option A is incorrect because it includes a subnet mask (/128) which is not part of the actual address notation. Option B is incomplete as it does not contain enough groups and ends with a single colon. Option C has too many groups (nine instead of eight) and is therefore not a valid IPv6 address. Option D is the correct notation with eight groups of four hexadecimal digits, where necessary leading zeros are included.
Reference:
IPv6 Address Types, Notation, and Structure Explained1.
IPv6 address formats - IBM2. =========================

Section: Cisco IOS Software Operation

DRAM, or Dynamic Random-Access Memory, is the type of memory that is erased when a Cisco device is rebooted. DRAM is used to store the running configuration and routing tables of the device. Since DRAM is volatile memory, its contents are lost when the device is powered down or restarted. This is in contrast to non-volatile memory types like flash and NVRAM, which retain their contents even after a reboot1. Reference := Types of memory on a Cisco device - Study-CCNA

The Cisco Nexus 9300 Series switches are a family of high-performance data center switching products. However, only a specific subset of models within this series supports 400-Gbps Ethernet ports.
Based on the information available online, two models from the Cisco Nexus 9300 Series that offer 400-Gbps Ethernet ports are:
Cisco Nexus 9316D-GX: This is a 1RU fixed switch that provides 16 ports of 400 Gbps (QSFP-DD) with a non-blocking switch architecture. It's suitable for aggregation, core, or spine applications.
Cisco Nexus 93600CD-GX: This is also a 1RU fixed switch, but it offers a combination of ports. It includes 28 ports of 100G and 8 ports of 400 Gbps (QSFP-DD) with a non-blocking switch architecture. This model is well-suited for data center Top-of-Rack (ToR), End-of-Row (EoR), and collapsed aggregation and access deployments, particularly when used with Cisco Nexus 2000 Fabric Extenders.
Reference:
Cisco Nexus 9000 Series 400G Deployment Guide