which is the best way to complete the text? laurens writing is effective because it is is able to…

Brief Explanations:

A semicolon is used to connect two independent clauses. "Lauren's writing is economical" and "she is able to communicate complex ideas with few words" are both independent clauses. The word "but" in the first option is redundant as the first part already gives a reason (because it's economical) for the effectiveness. The third option uses "because she" which is incorrect grammar as "because" is already used in the first part of the original sentence ("because it is...").

Answer:

economical; she