Option B should be the correct answer.
In topological sorting we should start with nodes whose in-degrees are 0. two such nodes are there h and c.
Now options starting with h are not valid. namely for first option e cannot be reached after a, since as per the matrix d should come before e.
for the last option after h, c should come since it's in-degree is zero and can be reached at this stage. e cannot be reached before reaching d and c.
coming to options with c
In the second option all the elements in the order from left to right are reached after the element (which has a directed edge towards it) has been reached.
Hence option A is correct.
