What Prevents Third Parties from Gaining Support and Being Able

What prevents third parties from gaining support and being able to challenge the two-party system?

A) Obsolete Texas state law prevents third parties from gaining seats in the legislature unless they win at least ten seats in the House and two in the Senate.
B) There has never been a true reason that would allow for the emergence of a third party, as the Republican and Democratic parties manage to represent the interests of everyone.
C) Strong campaigns require strong candidates and third parties in Texas have never had a rational, charismatic candidate to put up against the two parties.
D) State election laws supporting the status quo make it hard for third parties to get on the ballot, and elections determined by a simple plurality diminish their chances.
E) The Republican Party and Democratic Party typically bargain with third parties to reach a compromise on a policy issue in an attempt to prevent them from gaining traction.