E. The weather is 1) sunny 2) frosty 3) rainy

Решение:

В тексте письма говорится: "The weather hasn't been bad these days. It is quite warm. But yesterday when I was coming back from school, it started to rain heavily... I got a cold and I am absent from school today." Таким образом, погода была переменчивой, но вчера шел сильный дождь.

Ответ: rainy