Is it permissible to obtain a bank loan with 4% interest to finance a business, given the absence of alternatives such as interest-free loans and the difficulty of finding employment due to age, taking into consideration the financial and spiritual distress?

It is not permissible to engage in an interest-based transaction except in a state of necessity. The limit of necessity is when one predominantly believes that they will perish because of it, or that they will suffer an unbearable hardship because of it, or that they will be unable to achieve the minimum standard of living of the poor.