How debt to capital employed ratio calculated?

Both options 1 and 2

The correct answer is option 4- Both options 1 and 2.

The Debt to capital employed ratio refers to the ratio of long-term debt to the total of external and internal funds (capital employed or net assets).
It is computed as follows: Debt to Capital Employed Ratio = Long-term Debt/Capital Employed (or Net Assets).
Capital employed is equal to the long-term debt + shareholders’ funds. 

It may be noted that Debt to Capital Employed Ratio can also be computed in relation to total assets. In that case, it usually refers to the ratio of total debts (long-term debts + current liabilities) to total assets, i.e., total of non current and current assets (or shareholders’, funds + long-term debts + current liabilities), and is expressed as :
Total Debts/Total Assets