The girl is thinking about ( )she will go abroad to study En

B
在所有这种带有question或doubt之类的句子中 只要是语义带有疑问的 都用whether 语义是肯定的就用that
如There's no doubt that he'll come tonight.（毫无疑问他今天晚上会来.）
It's a question whether he'll come (or not).（他来不来还是个问题呢.）(只有连接词用whether的时候才能加or not )