When Lou and Nancy bought their house $3$ years ago they had an interest rate of $5\mathrm{.}3\%$ When they renewed their mortgage the interest rate had increased to $7\mathrm{.}4\%.$ What type of risk does this represent?

Question $1$ options:

a$)$

liquidity risk

b$)$

interest rate risk

c$)$

product risk

d$)$

inflation risk