__________ is the faithful and continued effort put forth in order to achieve a goal.

A) Persistence
B) Intensity
C) Orientation
D) Activation

Persistence is the most appropriate choice as it refers to the act of continuously putting in effort towards achieving a goal, even in the face of difficulty or obstacles. Intensity refers to the degree of effort put forth, but does not necessarily imply consistency over time. Orientation and Activation do not accurately reflect the concept described in the question.