If a girl's eyes sparkle when she looks at you, it means she is interested in you.

四个答案中，唯独sparkle 表示的“闪光”带有“兴奋、喜悦、高兴之色”，根据语境就填sparle。

又如：

Speaking of his lover, his eyes sparkled. 

谈到他的情人时，他的双眼闪烁着光芒。

Her eyes sparkled at the compliment. 

受到恭维，她眼睛里露出了喜色。

Her eyes sparkled with happiness. 

她的双眼闪耀着幸福的光芒。

Father's eyes sparkled with joy. 

父亲的眼中闪烁出喜悦之色。

She blushed faintly, her eyes sparkled. 

她的脸微微泛红，眼睛闪闪发光。

Her eyes sparkled with excitement. 

她的眼睛由于兴奋而发亮。

The driver's eyes sparkled at the sight of the wine. 

马车夫看见葡萄酒，眼睛里露出喜悦的神情。

Her eyes sparkled with joy. 

她高兴得两眼闪光。

The happy dog wagged his tail, while the elephant's eyes sparkled with delight. 

快乐的小狗摇着尾巴，大象的眼睛也闪烁喜悦。