$(13$ pts$.)$ Consider the following directed graph:

a$.(2$ pts$)$ What are the sources and sinks of the graph?

b$.(4$ pts$)$ Perform DFS with timing on the graph. When there's a choice of vertices, pick the alphabetically first one. Provide the pre and post numbers for each vertex, and the postlist.

c$.(4$ pts$)$ How many linearizations does this graph have?

d$.(3pts)$ Draw the meta$-$graph of this graph and list the vertices in each connected component. I need you to draw it for me on paper.