 Hello and welcome to the session. Let's work out the following question. It says choose the correct option, justify your choice. So let's now move on to the solution. It's a multiple choice question and we have to choose the correct answer. The given expression is 9 secant square a minus 9 tan square a. Now we take 9 common so we have 9 into secant square a minus tan square a. Now we know that tan square secant square theta minus tan square theta is 1. It is 9 into 1. So this is equal to 9. So the correct option is b. This completes the question and the session. Bye for now. Take care. Have a good day.