Question 161580
I think {{{h= -9.8t^2 + 88.2t}}} (you did not put the last t)

you have to solve the following inequality:

{{{-9.8t^2 + 88.2t > 176.4}}}
then 
{{{-t^2+9t>18}}}
then
{{{-t^2+9t-18>0}}}
then
{{{-(t-3)(t-6)>0}}}
then
{{{(t-3)(t-6)<0}}}
then {{{3<t<6}}}

Answer: correct option is a)