Q$3(14$ marks$)$ Circle the most correct answer for the following statements:

A storm with the time distribution shown in the table generates direct runofl of $4\mathrm{.}9cm.$ Find the $-$index for the storm.

$\backslash$table$[[$Time from start $(h),1,2,3,4,5,6],[$Incremental rainfall in each hour $),12,8,17,20,15,10]]$

c$)0\mathrm{.}72c\frac{m}{h}$

b$)0\mathrm{.}65c\frac{m}{h}r$

i$)$ None of these

a$)0\mathrm{.}82c\frac{m}{h}r$

e$)0\mathrm{.}52c\frac{m}{h}r$

d$)0\mathrm{.}58c\frac{m}{h}r$