Answer: Option 'A' is correct.
Explanation:
Since we have given that
Number of hours Wade take to paint a certain room = 7 hours
Number of hours Rhondda take to paint a certain room = 5 hours
Work done by Wade is given by

Work done by Rhondda take to paint a certain room =

Work done if they working together is given by

Number of hours if they working together to paint the room is given by

Hence, option 'A' is correct.