After reading the following passage, answer the questions which follow:

I must say that, beyond occasionally exposing me to laughter, my constitutional shyness has been of no great disadvantage to me. In fact, I can see that, on the contrary, it has been all to my advantage. My hesitancy in speech, which was once an annoyance, is now a pleasure. Its greatest pleasure has been that it has taught me the economy of words. I have naturally formed the habit of restraining my thoughts. And I can now, give myself the certificate that a thoughtless word hardly ever escapes of my tongue or pen. I do not recollect ever having had to regret anything in my speech or writing. I have thus been spared many a mishap and waste of time. Experience has taught me that silence is part of the spiritual discipline of a votary of truth. Proneness to exaggerate, to suppress or modify the truth, wittingly or unwittingly, is a natural weakness of man and silence is necessary in order to surmount it. A man of few words will rarely be thoughtless in his speech; he will measure every word.

From the options given below, select the one which will appropriately answer the following question:

The author due to his shy nature ________

Naturally formed the habit of restraining his thoughts