Peter received a letter just now his grandma would come to see him soon.
A.said B.says C.saying D.to say
Peter received a letter just now his grandma would come to see him soon.
A.said B.says C.saying D.to say
C
根据句子结构,此处应用非谓语动词作定语。现在分词表示动作正在进行或经常发生,此处的saying相当于which said;不定式作定语表示将来,不合题意。