In the current shown Fig., `X` is joined to `Y` for a long time and then `X` is joined to `Z`. The total heat produced in `R_(2)` is
A. `(L varepsilon^(2))/(2R_(1)^(2))`
B. `(Lvarepsilon^(2))/(2R_(2)^(2))`
C. `(Lvarepsilon^(2))/(2R_(1)R_(2))`
D. `(Lvarepsilon^(2)R_(2))/(2R_(1)^(3))`
