The Ricker scale, as well as other measurement, (has, have) been used to record the magnitude of earthquakes. Subject verb agreement

Excerpt from the prophet kahlil gibran and think not you can direct the course of love, for love, if it finds you worthy, directs your course. in this line from the passage, what does the word course mean? a) a mode of action or behavior b) a part of a meal served as a unit c) a designated area of land or water d) a continuous layer of building material