3/9 will fit on one bus so it will take 3 buses to fit 9/9 of the students, which 9/9 is the whole group.
Answer: Option 'D' is correct.
Step-by-step explanation:
Since we have given that

and

So, we need to find,

(∵they are independent events .)

So, option 'D' is correct.
That's increased level of warming