$19)$ If a bond's volatility is $10\mathrm{.}00$ percent and the interest rate goes down by $0\mathrm{.}75$ percent $($points$),$ then the price of the bond:

A$)$ decreases by $10\mathrm{.}00$ percent.

B$)$ decreases by $7\mathrm{.}50$ percent.

C$)$ increases by $7\mathrm{.}50$ percent.

D$)$ increases by $0\mathrm{.}75$ percent.