Are parallel sets of mountain ranges within the andes mountains.
a. pampas
b. llanos
c. estuaries
d. cordilleras

"Cordilleras" are parallel sets of mountain ranges within the Andes Mountains. A cordillera is a chain of mountain ranges -  and it is an extensive chain. The term itself originates from Spanish that has the same meaning. It is applied to different ranges that includes the Andes of South America but seldom on other mountain ranges in the ridge.

Answer they are produced by collision of tectonic plates;

Answer (d) the greenhouse effect is primarily caused by car and trucks;