This statement describes a major contribution of natan sharansky.

a. he organized the israeli defense during the yom kippur war
b. he negotiated a long term peace treaty between israel and palestine
c. he worked to soviet jews immagrate to israel
d. he drafted the israeli declaration of independence

The best and most correct answer among the choices provided by your question is the third option or letter C. Natan Sharansky worked  to help Soviet Jews immigrate to Israel.

Natan Sharansky is an Israeli politician, human rights activist and author who, as a refusenik in the Soviet Union during the 1970s and 1980s, spent nine years in Soviet prisons.

I hope my answer has come to your help. Thank you for posting your question here in .

They made a checks and balance system to equal power within the branches. the "check" meant that one branch would watch one branch and "balance" them if they were too powerful. if you want more info on this, i would just google checks and balance system.