Assume the securities are all issued by the same firm. From the investor's standpoint, rank the following securities in order of increasing risk $($the number of the least risky security is placed first, or to the left, in the answer set$)$: $(1)$ Municipal bond. $(2)$ Debenture. $(3)$ Convertible bond. $(4)$ Treasury bonds.

Group of answer choices

$4,2,3,1$

$4,1,3,2$

$4,1,2,3$

$4,2,1,3$

$2,4,1,3$