1. Fatigue design requires closer spacing at midspan while strength design requires uniform spacing
2. Fatigue design governs spacing in regions of stress reversal while strength design assumes redistribution
3. Strength design controls near supports while fatigue design controls near midspan
4. Fatigue design depends on steel grade while strength design depends only on concrete strength

Explanation

Explanation:
Shear stud spacing requirements differ between fatigue and strength design because fatigue design must address actual elastic stress ranges under service loads, while strength design can rely on plastic redistribution of forces. Per AASHTO LRFD Section 6.10.10, fatigue design prevents localized connector failure under repeated loading, requiring closer spacing in regions of stress reversal (often near supports). For ultimate strength design, a more uniform spacing is acceptable because shear connectors can redistribute forces through yielding, allowing all connectors to participate in developing the composite section's full plastic capacity. This dual design approach ensures both operational longevity and ultimate capacity. Options (A) and (C) incorrectly characterize the governing regions; option (D) misrepresents the controlling factors for each design scenario. 

Learning Resources:
• Review AASHTO LRFD Bridge Design Specifications, 9th Edition (2020), Section 6.10.10 for shear connector requirements.
• Tip: When designing shear connectors, consider fatigue requirements which often govern design in regions of stress reversal.