Heat is lost at a rate of $275 \mathrm{~W}$ per $\mathrm{m}^{2}$ area of a 15 -cm-thick wall with a thermal conductivity of $k=1.1 \mathrm{~W} / \mathrm{m} \cdot \mathrm{K}$. The temperature drop across the wall is
(a) $37.5^{\circ} \mathrm{C}$
(b) $27.5^{\circ} \mathrm{C}$
(c) $16.0^{\circ} \mathrm{C}$
(d) $8.0^{\circ} \mathrm{C}$
(e) $4.0^{\circ} \mathrm{C}$