请教：CFA1级 原版书 Reading57 第36题 correct, because, specific, relative, generate

sting_zhuang

摘取部分题目如下：

Given a callable bond's price and relative to a given spot rate curve, more than one option-adjusted spread(OAS) might exist depending on the outcomes of the specific model used to generate the option-adjusted spread.

关于上面表述，答案解释为：
The statement is correct because OAS is model dependent.

请问老师，什么叫做 “OAS is model dependent” ?