Which of the following bonds has the shortest duration?

Question $42$Select one:

a$.$

"Coupon $=15\%,$ time to maturity $=15$ years, yield to maturity $=10\%"$

b$.$

"Coupon $=15\%,$ time to maturity $=20$ years, yield to maturity $=10\%"$

c$.$

"Coupon $=12\%,$ time to maturity $=20$ years, yield to maturity $=10\%"$

d$.$

"Coupon $=15\%,$ time to maturity $=15$ years, yield to maturity $=15\%."$