Question

why did thurgood marshall cite the fourteenth amendment to argue that segregation in public schools was unconstitutional?
the fourteenth amendment guarantees equal protection under the law.
the fourteenth amendment guarantees every child an education.
the fourteenth amendment gave african americans the right to vote.
the fourteenth amendment formed the basis for plessy v. ferguson.

Explanation:

Thurgood Marshall argued that state-mandated public school segregation violated the Fourteenth Amendment's Equal Protection Clause, which requires states to provide equal legal protection to all citizens. Segregated schools were inherently unequal, thus violating this constitutional guarantee. The other options are incorrect: the 14th Amendment does not explicitly guarantee education, voting rights for Black Americans came from the 15th Amendment, and Plessy v. Ferguson upheld "separate but equal" (a ruling Marshall sought to overturn in Brown v. Board of Education).

Answer:

The Fourteenth Amendment guarantees equal protection under the law.