Given
It is given that machine print 63 booklets in 6 hours.
Step-by-step explanation
To determine the proportion could be used to determine ask the number of booklet that the machine can print it nine hours.
Use the unitary method,
In 6 hours booklets print is 63.
In 1 hour , booklets print is

In 9 hour , the booklets print is
Answer Hence the proportion formed is

The correct option is b.