What is total membership of US Senate?

What is total membership of US Senate?A. 100
B. 102
C. 104
D. 109

The United States Constitution prescribes that the Senate be composed of two senators from each State (therefore, the Senate currently has 100 Members) and that a senator must be at least thirty years of age, have been a citizen of the United States for nine years, and, when elected, be a resident of the State from which he or she is chosen. A senator’s term of office is six years and approximately one-third of the total membership of the Senate is elected every two years.