给定段落和答案，生成符合该答案的问题。请以{"问题": " "}的格式作答。
{"段落": "目前功效最强大的是：西地那非。远远大于普通壮阳药的功力。Sildenafil is currently the best aphrodisiac，The effect is far greater than the ordinary aphrodisiac.", "答案": "西地那非"}
{"问题": "壮阳药那种最好"}