The one-factor Hull-White model follows the stochastic differential equation dr = (0(t) - Yri)dt + odW, where re is the short rate, W, a standard Brownian motion, and o > 0 are constants and 6 a variable dependent on time t. The annualised volatility 0:(T) of the changes in dri(T) in the long- term bond yield rit) for the one-factor Hull-White model, where t is time to maturity is defined as 0,(T) = (1-e"). Show that or(T) decreases as t increases when 7 > 0. The one-factor Hull-White model follows the stochastic differential equation dr = (0(t) - Yri)dt + odW, where re is the short rate, W, a standard Brownian motion, and o > 0 are constants and 6 a variable dependent on time t. The annualised volatility 0:(T) of the changes in dri(T) in the long- term bond yield rit) for the one-factor Hull-White model, where t is time to maturity is defined as 0,(T) = (1-e"). Show that or(T) decreases as t increases when 7 > 0