Which digital system translates coded characters into a more useful form? Identify the subsystem that takes a coded binary input (such as BCD or 7-bit ASCII) and converts or expands it into a more directly usable set of output signals.

Introduction / Context:
Many digital systems use compact codes for efficiency. A decoder translates these codes into broader, more directly useful output patterns, such as driving individual display segments or selecting one of many lines. Recognizing the role of decoders is fundamental in digital design.

Given Data / Assumptions:

• Input is a coded representation (e.g., BCD 0000–1001 for 0–9).
• Output must be a more useful form (e.g., 1-of-10 lines, 7-segment patterns).
• We distinguish between encoders and decoders.

Concept / Approach:
An encoder compresses many input lines into a smaller coded output; a decoder performs the reverse, expanding coded input into a richer set of outputs. Therefore, the block that translates a compact code into actionable signals is a decoder.

Step-by-Step Solution:

Verification / Alternative check:
Common ICs: 7447 (BCD-to-7-seg), 7442 (BCD-to-decimal) are canonical decoders that translate coded characters to display/control outputs.

Why Other Options Are Wrong:

• Encoder: opposite operation (many inputs → coded output).
• Display: a load, not the translator itself.
• Counter: sequential device that advances states, not a code translator.

Common Pitfalls:
Assuming “display” performs decoding; often a dedicated decoder/driver IC feeds the display hardware.

Final Answer:
decoder