A1. Rhododendron can survive winter only if the temperature does not fall below $-28^{\circ} \mathrm{C}$ and summer only if the temperature does not exceed $24^{\circ} \mathrm{C}$. What temperature difference can the rhododendron still survive?
(A) $4^{\circ} \mathrm{C}$
(B) $45^{\circ} \mathrm{C}$
(C) $54^{\circ} \mathrm{C}$
(D) $-4^{\circ} \mathrm{C}$
(E) $52^{\circ} \mathrm{C}$
A1. The greatest temperature difference that the rhododendron can survive is $24-(-28)=52$ degrees.