Order-of-magnitude estimates in physics Steps:

• Recall standard values: atmospheric pressure (A), light travel time from Sun (B), UV frequency (C), human lifespan (D).
• Compute expected orders: pressure 10^5 Pa; Sun distance 1.5×10^11 m, c=3×10^8 m/s so time 500 s or 10^2 s; UV λ≈10^{-7} m so f=c/λ=3×10^{15} Hz; lifespan 80 yr × 3×10^7 s/yr ≈ 2×10^9 s.
• Compare to given values for discrepancies.
• Select largest mismatch as unreasonable.

Why B is correct:

• Light travel time = distance/speed of light = 1.5×10^{11}/3×10^8 = 5×10^2 s (8 min), but 10^{16} s equals ~300 million years, violating basic optics formula.

Why the others are wrong:

• A: Matches standard 1.01×10^5 Pa definition exactly in order.
• C: Matches c/λ for UV wavelength (100 nm) per electromagnetic spectrum.
• D: Close to 10^9 s order (off by factor ~10, acceptable rough estimate).

Final answer: B