Adder performance: A carry look-ahead (CLA) adder uses extra logic to compute carries in parallel and is generally faster than a ripple-carry adder. Evaluate the claim that a look-ahead-carry adder is slower because it requires additional logic.

Introduction / Context:
Adder architectures trade off complexity and speed. Ripple-carry adders propagate carry serially through each bit, while carry look-ahead (CLA) adders compute carry signals in parallel using generate/propagate logic to reduce delay.

Given Data / Assumptions:

• Ripple adders have O(n) carry-chain delay for n bits.
• CLA adds extra logic (generate/propagate) to shorten the critical path.
• We compare speed, not just gate count.

Concept / Approach:
CLA adds logic to compute carries simultaneously across groups, transforming linear carry delay into a shorter, usually logarithmic or block-based delay. Although hardware cost rises, the net effect is faster addition for moderate and wide bit-widths compared to ripple schemes.

Step-by-Step Solution:

Verification / Alternative check:
ASIC/FPGA timing models consistently show CLA outperforming ripple for nontrivial widths; further enhancements (carry-select, carry-skip, parallel-prefix) push speed even higher.

Why Other Options Are Wrong:

• Correct: Misinterprets added logic as a speed penalty; it is a speed optimization.
• Ambiguous / Cannot be determined: The architectural comparison is well-established.

Common Pitfalls:
Equating gate count with speed; in arithmetic circuits, structured parallelism often improves timing at the cost of area.

Final Answer:
Incorrect