You're welcome to come with us now in our car. ________ you could go later with Mary. It's

You're welcome to come with us now in our car. ________ you could go later with Mary. It's up to you.

A.Alternatively

B.Alternative

C.To choose

D.To alter

答案及解析： A

alternatively副词，修饰第二个句子，意为"或者，另外一个办法"。