Sometimes it is better not to think too much about the utility of a question.

We know the number of the set is odd (35).
Thanks to the graph we have the number of hours work for each of the 35 workers
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 4, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7

So take the middle one of the 35 numbers and you have your median, I mean 6.

--> E
Tell me if that's right but I think so.

you're right, pepeprepa..good one...

You can use the following approach as well:
Value Frequency Cumulative Frequency
1 9 9
2 4 13
3 1 14
4 2 16
5 1 17
6 8 25
7 10 35

So, the median will be the middle value which is 35/2 = 17.5 or which lies from 17th to 25th value if you arrange all in order.

Hence, median = 6
Ans: E

This approach can be used for all problem which require you to calculate median from a frequency distribution.