What is a complex character?

pls help

Which of the following is an element of plot

Which of the following examples represents a flat character

Which sentence is written correctly? a. it's too bad its raining, i wanted too go for a swim. b. its too bad its raining, i wanted to go for a swim. c. it's too bad it's raining, i wanted to go for a swim. d. it's to bad it's raining, i wanted too go for a swim.