Correct Answer - 2
`(1)4Fe+underset("very dil.")(10HNO_(3))rarr4Fe(NO_(3))_(2)+NH_(4)NO_(3)+3H_(2)O`
`4Fe+underset("dil.")(10HNO_(3))rarr4Fe(NO_(3))_(2)+N_(2)O+5H_(2)O`
`(2)Mn+underset("dil.")(2HNO_(3))rarrMn(NO_(3))_(2)+H_(2)`
`(3)3Cu+underset("dil.")(8HNO_(3))rarr3Cu(NO_(3))_(2)+2NO+4H_(2)O`
`(4)2Al+8HNO_(3)rarr2Al(NO_(3))_(2)+2NO+4H_(2)O`