Data transfer modes in digital systems Systems that move multiple bits at the same instant across several conductors are said to transfer data ________.

Introduction / Context:
Digital designs use two fundamental data transfer modes: serial and parallel. Correctly identifying the mode from its description is essential for understanding bus design, throughput, and cabling trade-offs in computers, microcontrollers, and communication links.

Given Data / Assumptions:

• Parallel transfer uses multiple conductors to carry multiple bits simultaneously.
• Serial transfer uses one lane (or a differential pair) to send bits sequentially in time.
• “At the same instant” implies simultaneous multi-bit transfer.

Concept / Approach:
The phrase “move multiple bits at the same instant across several conductors” is the defining characteristic of parallel transfer. This is common on internal buses (e.g., an 8-bit data bus) where wiring cost and skew can be managed over short distances. Serial links dominate long-distance/high-speed connections where pin count must be minimized.

Step-by-Step Solution:

Verification / Alternative check:
Classic textbooks distinguish parallel (wider buses, higher instantaneous width) and serial (narrow link, serialized bits). Timing diagrams of parallel buses show several lines toggling in the same clock window for a word transfer.

Why Other Options Are Wrong:

• Serially: Bits are not transferred simultaneously; they are sequenced.
• Sequentially: Ambiguous phrase; could apply to control steps, not to the physical transfer width.
• Both serially and sequentially: Mixes concepts; not the definition in the prompt.
• Asynchronously only: Synchronization is orthogonal to parallel/serial classification.

Common Pitfalls:
Confusing differential signaling (two wires) with parallel transfer; a differential pair still carries one serialized bit stream per pair.

Final Answer:
in parallel