Answer:
B. programming languages
Step-by-step explanation:
The most necessary technical skill for network systems careers is programming languages (B). Programming languages are vital for developing, maintaining, and troubleshooting network infrastructure, protocols, and applications. Proficiency in programming enables automation, scripting for network configuration, and customized software solutions. While other skills like website design, IT security, and graphics software may have some relevance, programming languages are fundamental for effective network management.