A tube-in-tube counter-flow heat exchanger is heating oil from $35^{\circ} \mathrm{C}$ to $77^{\circ} \mathrm{C}$ by circulating hot water at $100^{\circ} \mathrm{C}$. The outlet temperature of water is $70{ }^{\circ} \mathrm{C}$. The log-mean-temperature difference (LMTD) is
(A) exactly equal to the mean arithmetic temperature difference
(B) significantly greater than the mean arithmetic temperature difference
(C) significantly smaller than the mean arithmetic temperature difference
(D) very nearly equal to the mean arithmetic temperature difference
A tube-in-tube counter-flow heat exchanger is heating oil from $35^{\circ} \mathrm{C}$ to $77^{\circ} \mathrm{C}$ by circulating hot water at $100^{\circ} \mathrm{C}$. The outlet temperature of water is $70{ }^{\circ} \mathrm{C}$. The log-mean-temperature difference (LMTD) is
(A) exactly equal to the mean arithmetic temperature difference
(B) significantly greater than the mean arithmetic temperature difference
(C) significantly smaller than the mean arithmetic temperature difference
(D) very nearly equal to the mean arithmetic temperature difference
(D) very nearly equal to the mean arithmetic temperature difference