Please refer to "Exercise" and answer those questions on the slide. For the payoff diagram, you can simply describe how it looks like (e.g., flat from $x to $y, upward sloping from $z to $t)

Exercise What does the option contract payoff diagram look like for Need Oil. Co. if it chooses to buy a call option with a strike price of $15 and sell another call option with a strike price of $18? (Ignore the option premiums.) What risk does this option combo hedge against, and what may be the reason that Need Oil engages in the above transactions