Anand takes the pole position here...
In this series, the verbs not underlined are going and reaching. Because of this, we can eliminate all answer choices in which the verb cause does not follow the "-ing" pattern. Causing, choice C, is the only option with the gerund or "-ing" form, thus making it the correct answer.
"Start By Doing What Is Necessary ,Then What Is Possible & Suddenly You Will Realise That You Are Doing The Impossible"