The following questions are based on four passages in English to test the comprehension of English language. Read each passage and answer the questions.
As the tortoise tucks its feet and head inside the shell and will not come out even though you may break the shell into pieces, even so the character of the man who has control over his motives and organs, is unchangeably established. He controls his own inner forces, and nothing can draw them out against his will. By this continuous reflex of good thoughts and good impressions moving over the surface of the mind, the tendency to do good becomes strong, and in consequence, we are able to control the Indriyas or sense organs.
The author uses the phrase ‘inner forces’ in this passage. Which of the following would be its most correct meaning in the context?