Symport is a type of transport mechanism that occurs in a cell's membrane. In symport, two different molecules or ions are transported across the membrane in the same direction, but they are co-transported by the same carrier protein. So, the correct option is : Option C : in same direction with the help of the same carrier. The other three options describe different types of transport: Option A : describes a situation where two different carriers at a common site are involved, which does not represent symport. Option B : describes a situation where two different carriers at different sites in the same cell are involved, which also does not represent symport. Option D : describes a situation where two molecules move in the opposite direction. This is a characteristic of antiport, not symport.