What was the initial purpose of samba schools in their early years (1920s)?

a. To integrate early genres of samba with international genres such as merengue and reggae.

b. To support literacy initiatives among poorer socioeconomic classes in Rio de Janeiro.

c. To support and lend legitimacy to engagement in Carnival on the part of black Brazilians.

d. To call attention to racism and "purify" samba of non-African elements.

e. None of the above.