In a production facility, large plates made of stainless steel (k = 15 W/m · K, α = 3.91 × 10^-6 m²/s) of 40 cm thickness are taken out of an oven at a uniform temperature of 750°C. The plates are placed in a water bath that is kept at a constant temperature of 20°C with a heat transfer coefficient of 600 W/m² · K. The time it takes for the surface temperature of the plates to drop to 100°C is
(a) 0.28 h

(b) 0.99 h

(c) 2.05 h

(d) 3.55 h

(e) 5.33 h