Work completed in 5 days = $\left(\frac{1}{6}\right)$. Since $50\%$  of the bridge collapsed so total work completed after 5 days =

$\left(\frac{1}{12}\right)$ Remaining work after 5 days = $\left(\frac{11}{12}\right)$

Since women efficiency is half so 10 women will finish the work in 60 days i.e each day  they will finish $\left(\frac{1}{60}\right)$ part of work.

15 men will finish = $\left(\frac{1}{20}\right)$ part of work every day. So from the sixth day onwards the work finished everyday $=\frac{1}{20}+\frac{1}{60}=\frac{1}{15}.$ Now from sixth days onwards it rains alternatively for 2 working hours.

Hence total numbers of hours lost =  $6\times 2$  = 12 hrs = 1.5 days ( 8 hrs per day)

So till 17th day instead of remaining 12 days the work was done effectively on only 10.5 days.

So the work completed in 10.5 days $=\frac{10}{15}+\frac{1}{30}=\frac{21}{30}.$

Fraction of work left after 17th day = work left after 5 days - work done in 12 days $=\frac{11}{12}-\frac{21}{30}=\frac{13}{60}$

Hence option D is correct.

Alternative approach: (using units of work done)

Total number of units of work to be done = $10\times 30\times 8$ = 2400

In the first 5 days, $10\times 5\times 8$ =400 units of word is done. However, 200 units of work is lost

Thus, remaining work is 200 units

From the $6^{th}$ day 5 more men and 10 more women are joining in $\Rightarrow$ 10 more men are joining in

Thus, on every day that it rains; number of units of work done $=6\times 20=120$

And on every day that it does not rain; number of units of work done $=8\times 20=160$

Total units of work done  $=120\times 6+160\times 6+200=1880$

Remaining work = 2400-1880 = 540. Required ratio =$\left(\frac{540}{2400}\right)=\left(\frac{13}{60}\right)$