$($i$)$ State $2$ main types of dispersion that cause pulse spreading in a fiber. $(2$ marks$)$

$($ii$)$ Name which type of fiber that has pulse spreading problem only caused by one

type of dispersion and explain why it is so$.(2$ marks$)$

$($iii$)$ State the name of this dispersion that causes pulse spreading problem for this

particular fiber. $(1$ marks$)$