Alkali metals and alkaline earth metals are s-block elements, electropositive in nature and form electrovalent compounds. Some of such metals are very essential for living organisms. Which of the following is incorrect regarding biological significance of Mg, Ca, Na and K ions
| A. |
`Na^+` is present outside the cell while `K^+` is present inside the cell |
| B. |
`Na^+` is present inside the cell while `K^+` is present outside the cell |
 |
| C. |
`Ca^(2+)` is present as apatite in teeth |
| D. |
`Mg^(2+)` is an essential contstituent found in leaf of plants |
`Ca^(2+)` is present in teeth as apatite `Ca_3 (PO_4 )_2` . Magnesium is present in plant as chlorophyll. `K^+` is present inside the cell and `Na^+` is present outside the cell.