One reason why adjustable$-$rate mortgages $($ARMs$)$ have become popular has to do with the impact that they have on the interest rate risk that is borne by the parties involved. If interest rates were to rise on a level$-$payment mortgage $($LPM$),$ the interest rate risk of the loan would typicall$$ be borne by:

the borrower only.

neither the borrower nor the lender.

both the borrower and lender.

the lender only.