求高手，英语词汇单选题

It took me a day or two to_____her that I wasn't going to harm her.
A persuade B insure C assume D convince
选A
句意：这花了我一两天时间让她相信我不会伤害她。
A persuade v. 说服，劝说；使某人相信
B insure v 确保，保证；给…保险
C assume v. 承担；假定；采取
D convince v. 说服；使确信，使信服

persuade和convince 的区别很小，有时可以通用。我查了字典，发现
persuade ：1.to make someone to do something ,especially by giving them reasons why they should do it,or asking them many times to do it.说服、劝服
2. to make someone believe sth or feel sure about something 使相信、使信服
convince：1.to make somebody feel certain somethingis true.使确信
2.to persuade sb to sth 说服、劝服

对比英文解释你可以发现persuade强调你说服某人花了很大力气,asking them many times to do it,而convince没有，本句中It took me a day or two，花了我一两天的时间，表示花了比较长的时间，花了挺大的力气，并不是一下子就说服了，所以选择persuade更好些。
同理：He strongly urged me to do it,but he didn't persuade me.这里也用persuade，而不用convince
注意：persuade 和convince都可以跟从句，都可以接 of

For your imformation 供参考

选A，使某人相信，句意我花了一两天的时间才使她相信我不会伤害她。B是保证，C是假定，想当然的认为D也是相信，但不能直接跟人或从句