We no longer keep up the close friendship of a few years ago though we still visit each other on occasion .
【正确答案】 C
【答案解析】解析：译文为：虽然我们仍然偶尔相互拜访，但好几年前就没有保持亲密关系了。on occasion有时。in good time及时；up to date最新的；now and then不时；once and for all坚决地。