I can lend you the money________ you give it back at the end of three weeks．
A.in a condition thatB.on condition thatC.on one conditionD.on the condition if在线课程B
on one condition介词短语作状语，意为“规定一个条件”，如：He allowed me to do it on one condition．他有条件地允许我做这件事。on condition that相当于as long as，意为“只要”，引导一个条件状语从句。