1a) F sequential, the past affects the present
1b) T uncertainty due to opponent
2a) F it may have been hit by a meteor and it could still be optimal in an average sense
2b) T since we know there is a better algorithm (one that includes planning) 
3a) F big-O notation is only about asymptotic behavior. For small b,d lower order terms may dominate
3b) F it will avoid repeated states
4a) T any graph search algorithm stores all nodes that have been expanded up till now
4b) T optimality ensures finding a solution if there is one