Answer: C
P. False. Weight will increase by $(n-1)*k$
Q. False. Consider the below graph.
MST is
(1) (4) \ / (2) / \ (3) (5)
Shortest path from $1-4$ will be $7$ in MST but it should be $5$.
Reference: https://cs.stackexchange.com/questions/18797/minimum-spanning-tree-vs-shortest-path