Which of the following describes the amount of data that can be sent across a link in a given time?

Bandwidth is the precise technical term for the maximum data throughput capacity of a network link over time, measured in units such as Mbps or Gbps, which directly matches the question's description of data sent across a link in a given time.

Quality of Service (QoS) refers to traffic prioritization and management policies that control how bandwidth is allocated, not the raw capacity of the link itself.

Latency measures the delay - the time it takes a packet to travel from source to destination - which is a timing metric, not a data volume metric.

Network speed is an informal, colloquial term that can refer to multiple metrics; bandwidth is the specific technical term for data transfer capacity over time.