Which source of funding would be appropriate to finance a large$-$scale capital investment program?

$1.$A $10-$year loan, secured against the assets purchased as part of the capital investment program.

$2.$A $12-$month loan, repayable with a bullet payment at the termination date.

$3.$An overdraft facility with the company's primary bank.

$4.$Funding raised using invoices outstanding with clients as security for the loan.