The direct mechanism of calcium overload is ( )
选项：

A: disorder of K⁺-Ca²⁺ exchange
B: disorder of Na⁺-Ca²⁺ exchange
C: disorder of H⁺-Ca²⁺ exchange
D: disorder of P³⁺-Ca²⁺ exchange
E: disorder of Mg²⁺-Ca²⁺ exchange