---today!---Yes. Shall we have a picnic in the open air?A. What fine weather isB. How fine

问题补充：

---today!

---Yes. Shall we have a picnic in the open air?

A. What fine weather is

B. How fine weather it is

C. What a fine weather it is

D. How fine the weather is

答案：

A. What fine weather is

B. How fine weather it is

C. What a fine weather it is

(答案→)D. How fine the weather is

解析：根据句式可知，本句是感叹句。根据weather是不可数名词，其前不能用不定冠词，所以应该将C排除；又根据How强调是后面的形容词或副词，而what强调的是名词，根据weather，故排除B；在本句中的weather是今天的天气，故是特指，应用the。所以本题应该选D。