To forgive an injury is often considered to be a sign of weakness; it is really a sign of strength. It is easy to allow oneself to be carried away by resentment and hate into an act of vengeance; but it takes a strong character to restrain those natural passions. The man who forgives an injury proves himself to be the superior of the man who wronged himself and puts the wrong-doer to shame. The passage best supports' the statement that:

The passage discusses the concept of forgiveness, presenting it as a sign of strength rather than weakness. It contrasts forgiveness with vengeance, highlighting the difficulty in restraining natural passions such as resentment and hate. Here's the analysis of the options based on the passage:

1. Option A - the sufferer alone knows the intensity of his sufferings:
   • The passage does not focus on the intensity of the sufferer's suffering. Instead, it emphasizes the strength required to forgive and control negative emotions like resentment and hate. There is no direct reference to the sufferer’s understanding of their own suffering.
   
   
   • This option is not supported by the passage.


2. Option B - people tend to forgive the things happened in the past:
   • The passage does not discuss people forgiving past wrongs in general. It talks about the strength involved in forgiving an injury and restraining negative emotions like resentment, but does not focus on the forgiveness of past events in a broad sense.
   
   
   • This option is not directly supported by the passage.


3. Option C - natural passions are difficult to suppress:
   • The passage mentions that it is easy to be carried away by resentment and hate and that it requires strong character to restrain these natural passions. This directly supports the idea that natural passions are difficult to suppress.
   
   
   • This option is strongly supported by the passage.


4. Option D - mercy is the noblest form of revenge:
   • The passage does not discuss mercy as a form of revenge. Instead, it focuses on forgiveness as a sign of strength and self-restraint, contrasting it with vengeance, but it does not frame forgiveness as revenge.
   
   
   • This option is not supported by the passage.


5. Option E - a person with calm and composed nature has depth of thought and vision:
   • The passage does not explicitly discuss a person’s calm and composed nature in relation to depth of thought and vision. While it talks about strength of character in forgiving, it does not focus on the specific qualities of being calm and composed in the broader sense.
   
   
   • This option is not directly supported by the passage.


6. Final Answer:
   • The most supported statement by the passage is C. natural passions are difficult to suppress.