Who was the person that accompanied Alonso De Leon in the successful search for La Salle's Fort St. Louis, and the next year he assisted in the establishment of San Franciso de Los Tejas Mission? a
Don Quixote
b
Don Juan
c
Damian Massanet
d
Alberto Duran

The correct answer is: "interpret laws".

The US Constitution included since its enactment the principle of the division of powers, that fractionates the power of the state in three branches: legislative, executive and judiciary. A system of checks and balances needs to be established, so that each of the powers supervises the other two, in order to ensure that none of the branches gathers enough power as to overrule the others.

The judicial branch has the power of judicial review, which places the executive and legislative power under its surveillance, as part of the system of checks and balances.  A court with authority to exercise judicial review can abolish laws and goverment decision, if it considers that such actions from the legislative and executive powers respectively, are violating the Constitution.