Which sentence demonstrates a correctly formatted in-text citation using MLA format?

Students can also…

"participate in unique courses that may not be offered at their own school, such as language or business classes" ("Deleon, Fletcher").

"participate in unique courses that may not be offered at their own school, such as language or business classes" (by Fletcher Deleon).

"participate in unique courses that may not be offered at their own school, such as language or business classes" (Deleon, Fletcher).

"participate in unique courses that may not be offered at their own school, such as language or business classes" (Deleon).